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Tuesta M, Yáñez-Sepúlveda R, Monsalves-Álvarez M, Vásquez-Bonilla A, Olivares-Arancibia J, Rojas-Valverde D, Alvear-Órdenes I. Muscle Oxygen Extraction during Vascular Occlusion Test in Physically Very Active versus Inactive Healthy Men: A Comparative Study. J Funct Morphol Kinesiol 2024; 9:57. [PMID: 38525758 PMCID: PMC10961797 DOI: 10.3390/jfmk9020057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 02/14/2024] [Accepted: 02/21/2024] [Indexed: 03/26/2024] Open
Abstract
An increase in the delivery and use of oxygen to the musculature in physically active subjects are determinants of improving health-related aerobic capacity. Additional health benefits, such as an increase in the muscle mass and a decrease in fat mass, principally in the legs, could be achieved with weekly global physical activity levels of more than 300 min. The objective was to compare the muscle vascular and metabolic profiles of physically very active and inactive subjects. Twenty healthy men participated in the study; ten were assigned to the physically very active group (25.5 ± 4.2 years; 72.7 ± 8.1 kg; 173.7 ± 7.6 cm) and ten to the physically inactive group (30.0 ± 7.4 years; 74.9 ± 11.8 kg; 173.0 ± 6.4 cm). The level of physical activity was determined by the Global Physical Activity Questionnaire (GPAQ). A resting vascular occlusion test (5 min of an ischemic phase and 3 min of a reperfusion phase) was used, whereas a near-field infrared spectroscopy (NIRS) device was used to evaluate the muscle oxygenation in the right vastus lateralis of the quadriceps muscle. The area under the curve of the deoxyhemoglobin (HHb) during the ischemic phase and above the curve of the tissue saturation index (TSI) during the reperfusion phase were obtained to determine muscle metabolic and vascular responses, respectively. Physically very active group showed a higher absolute HHb (3331.9 ± 995.7 vs. 6182.7 ± 1632.5 mmol/s) and lower TSI (7615.0 ± 1111.9 vs. 5420.0 ± 781.4 %/s) and relative to body weight (46.3 ± 14.6 vs. 84.4 ± 27.1 mmol/s/kg and 106.0 ± 20.6 vs. 73.6 ± 13.8 %/s/kg, respectively), muscle mass (369.9 ± 122.2 vs. 707.5 ± 225.8 mmol/kg and 829.7 ± 163.4 vs. 611.9 ± 154.2 %/s/kg) and fat mass (1760.8 ± 522.9 vs. 2981.0 ± 1239.9 mmol/s/kg and 4160.0 ± 1257.3 vs. ±2638.4 ± 994.3 %/s/kg, respectively) than physically inactive subjects. A negative correlation was observed between HHb levels and TSI (r = -0.6; p < 0.05). Physically very active men (>300 min/week) present better muscle oxidative metabolism and perfusion and perform significantly more physical activity than physically inactive subjects. Extra benefits for vascular health and muscle oxidative metabolism are achieved when a subject becomes physically very active, as recommended by the World Health Organization. In addition, a higher level of physical activity determined by GPAQ is related to better vascular function and oxidative metabolism of the main locomotor musculature, i.e., the quadriceps.
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Affiliation(s)
- Marcelo Tuesta
- Exercise and Rehabilitation Sciences Laboratory, School of Physical Therapy, Faculty of Rehabilitation Sciences, Universidad Andres Bello, Viña del Mar 2520000, Chile;
- Laboratory of Sport Sciences, Centro de Medicina Deportiva Sports MD, Viña del Mar 2521156, Chile
| | - Rodrigo Yáñez-Sepúlveda
- Faculty Education and Social Sciences, Universidad Andres Bello, Viña del Mar 2520000, Chile;
| | | | | | - Jorge Olivares-Arancibia
- Grupo AFySE, Investigación en Actividad Física y Salud Escolar, Escuela de Pedagogía en Educación Física, Facultad de Educación, Universidad de las Américas, Santiago 8320000, Chile
| | - Daniel Rojas-Valverde
- Centro de Investigación y Diagnóstico en Salud y Deporte (CIDISAD-NARS), Escuela Ciencias del Movimiento Humano y Calidad de Vida (CIEMHCAVI), Universidad Nacional, Heredia 86-3000, Costa Rica;
- Clínica de Lesiones Deportivas (Rehab&Readapt), Escuela Ciencias del Movimiento Humano y Calidad de Vida (CIEMHCAVI), Universidad Nacional, Heredia 86-3000, Costa Rica
| | - Ildefonso Alvear-Órdenes
- Applied Physiology Laboratory (FISAP), Institute of Biomedicine (IBIOMED), University of León, 24001 León, Spain;
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Wakeham DJ, Ivey E, Saland SA, Lewis JS, Palmer D, Morris M, Bleich JL, Weyand PG, Brazile TL, Hearon CM, Sarma S, MacNamara JP, Hieda M, Levine BD. Effects of Synchronizing Foot Strike and Cardiac Phase on Exercise Hemodynamics in Patients With Cardiac Resynchronization Therapy: A Within-Subjects Pilot Study to Fine-Tune Cardio-Locomotor Coupling for Heart Failure. Circulation 2023; 148:2008-2016. [PMID: 37830218 PMCID: PMC11032184 DOI: 10.1161/circulationaha.123.066170] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 09/26/2023] [Indexed: 10/14/2023]
Abstract
BACKGROUND Despite advances in medical and cardiac resynchronization therapy (CRT), individuals with chronic congestive heart failure (CHF) have persistent symptoms, including exercise intolerance. Optimizing cardio-locomotor coupling may increase stroke volume and skeletal muscle perfusion as previously shown in healthy runners. Therefore, we tested the hypothesis that exercise stroke volume and cardiac output would be higher during fixed-paced walking when steps were synchronized with the diastolic compared with systolic portion of the cardiac cycle in patients with CHF and CRT. METHODS Ten participants (58±17 years of age; 40% female) with CHF and previously implanted CRT pacemakers completed 5-minute bouts of walking on a treadmill (range, 1.5-3 mph). Participants were randomly assigned to first walking to an auditory tone to synchronize their foot strike to either the systolic (0% or 100±15% of the R-R interval) or diastolic phase (45±15% of the R-R interval) of their cardiac cycle and underwent assessments of oxygen uptake (V̇o2; indirect calorimetry) and cardiac output (acetylene rebreathing). Data were compared through paired-samples t tests. RESULTS V̇o2 was similar between conditions (diastolic 1.02±0.44 versus systolic 1.05±0.42 L/min; P=0.299). Compared with systolic walking, stroke volume (diastolic 80±28 versus systolic 74±26 mL; P=0.003) and cardiac output (8.3±3.5 versus 7.9±3.4 L/min; P=0.004) were higher during diastolic walking; heart rate (paced) was not different between conditions. Mean arterial pressure was significantly lower during diastolic walking (85±12 versus 98±20 mm Hg; P=0.007). CONCLUSIONS In patients with CHF who have received CRT, diastolic stepping increases stroke volume and oxygen delivery and decreases afterload. We speculate that, if added to pacemakers, this cardio-locomotor coupling technology may maximize CRT efficiency and increase exercise participation and quality of life in patients with CHF.
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Affiliation(s)
- Denis J Wakeham
- University of Texas Southwestern Medical Center, Dallas (D.J.W., T.L.B., C.M.H., S.S., J.P.M., M.H., B.D.L.)
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas (D.J.W. E.I., S.A.S., J.S.L., D.P., M.M., T.L.B., C.M.H., S.S., J.P.M., M.H., B.D.L.)
| | - Erika Ivey
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas (D.J.W. E.I., S.A.S., J.S.L., D.P., M.M., T.L.B., C.M.H., S.S., J.P.M., M.H., B.D.L.)
| | - Sophie A Saland
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas (D.J.W. E.I., S.A.S., J.S.L., D.P., M.M., T.L.B., C.M.H., S.S., J.P.M., M.H., B.D.L.)
| | - Joshua S Lewis
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas (D.J.W. E.I., S.A.S., J.S.L., D.P., M.M., T.L.B., C.M.H., S.S., J.P.M., M.H., B.D.L.)
| | - Dean Palmer
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas (D.J.W. E.I., S.A.S., J.S.L., D.P., M.M., T.L.B., C.M.H., S.S., J.P.M., M.H., B.D.L.)
| | - Margot Morris
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas (D.J.W. E.I., S.A.S., J.S.L., D.P., M.M., T.L.B., C.M.H., S.S., J.P.M., M.H., B.D.L.)
| | | | - Peter G Weyand
- Locomotor Performance Laboratory, Department of Applied Physiology & Wellness, Southern Methodist University, Dallas, TX (P.G.W.)
| | - Tiffany L Brazile
- University of Texas Southwestern Medical Center, Dallas (D.J.W., T.L.B., C.M.H., S.S., J.P.M., M.H., B.D.L.)
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas (D.J.W. E.I., S.A.S., J.S.L., D.P., M.M., T.L.B., C.M.H., S.S., J.P.M., M.H., B.D.L.)
| | - Christopher M Hearon
- University of Texas Southwestern Medical Center, Dallas (D.J.W., T.L.B., C.M.H., S.S., J.P.M., M.H., B.D.L.)
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas (D.J.W. E.I., S.A.S., J.S.L., D.P., M.M., T.L.B., C.M.H., S.S., J.P.M., M.H., B.D.L.)
| | - Satyam Sarma
- University of Texas Southwestern Medical Center, Dallas (D.J.W., T.L.B., C.M.H., S.S., J.P.M., M.H., B.D.L.)
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas (D.J.W. E.I., S.A.S., J.S.L., D.P., M.M., T.L.B., C.M.H., S.S., J.P.M., M.H., B.D.L.)
| | - James P MacNamara
- University of Texas Southwestern Medical Center, Dallas (D.J.W., T.L.B., C.M.H., S.S., J.P.M., M.H., B.D.L.)
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas (D.J.W. E.I., S.A.S., J.S.L., D.P., M.M., T.L.B., C.M.H., S.S., J.P.M., M.H., B.D.L.)
| | - Michinari Hieda
- University of Texas Southwestern Medical Center, Dallas (D.J.W., T.L.B., C.M.H., S.S., J.P.M., M.H., B.D.L.)
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas (D.J.W. E.I., S.A.S., J.S.L., D.P., M.M., T.L.B., C.M.H., S.S., J.P.M., M.H., B.D.L.)
| | - Benjamin D Levine
- University of Texas Southwestern Medical Center, Dallas (D.J.W., T.L.B., C.M.H., S.S., J.P.M., M.H., B.D.L.)
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas (D.J.W. E.I., S.A.S., J.S.L., D.P., M.M., T.L.B., C.M.H., S.S., J.P.M., M.H., B.D.L.)
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Golub AS, Song BK, Nugent WH, Pittman RN. Dynamics of PO 2 and VO 2 in resting and contracting rat spinotrapezius muscle. Front Physiol 2023; 14:1172834. [PMID: 37538372 PMCID: PMC10396398 DOI: 10.3389/fphys.2023.1172834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 07/03/2023] [Indexed: 08/05/2023] Open
Abstract
This study examined changes in interstitial PO2, which allowed calculation of VO2 during periods of rest, muscle contraction and recovery using an in situ rat spinotrapezius muscle preparation. The PO2 was measured using phosphorescence quenching microscopy and the muscle VO2 was calculated as the rate of O2 disappearance during brief periods of muscle compression to stop blood flow with a supra-systolic pressure. The PO2 and VO2 measurements were made during "5 s compression and 15 s recovery" (CR) cycles. With all three stimulation frequencies, 1, 2 and 4 Hz, the fall in interstitial PO2 and rise in VO2 from resting values occurred within the first 20 s of contraction. The PO2 during contraction became lower as stimulation frequency increased from 1 to 4 Hz. VO2 was higher at 2 Hz than at 1 Hz contraction. With cessation of stimulation, PO2 began increasing exponentially towards baseline values. After 1 and 2 Hz contraction, the fall in muscle VO2 was delayed by one CR cycle and then exponentially decreased towards resting values. After 4 Hz stimulation, VO2 increased for 2 cycles and then decreased. The post-contraction transients of PO2 and VO2 were not synchronous and had different time constants. With further analysis two distinct functional responses were identified across all stimulation frequencies having PO2 during contraction above or below 30 mmHg. The corresponding VO2 responses were different - for "high" PO2, muscle VO2 reached high levels, while for the "low" PO2 data set muscle VO2 remained low. Recovery patterns were similar to those described above. In summary, local microscopic PO2 and VO2 were measured in resting and contracting muscle in situ and the post-contraction transients of PO2 and VO2 were all much slower than the onset transients.
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Affiliation(s)
- Aleksander S. Golub
- Department of Physiology and Biophysics, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA, United States
- Song Biotechnologies LLC, Cockeysville, MD, United States
| | - Bjorn K. Song
- Department of Physiology and Biophysics, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA, United States
- Song Biotechnologies LLC, Cockeysville, MD, United States
| | - William H. Nugent
- Department of Physiology and Biophysics, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA, United States
- Song Biotechnologies LLC, Cockeysville, MD, United States
| | - Roland N. Pittman
- Department of Physiology and Biophysics, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA, United States
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Behrendt T, Bielitzki R, Behrens M, Schega L. Acute performance, physiological, and perceptual changes in response to repeated cycling sprint exercise combined with systemic and local hypoxia in young males. Physiol Behav 2023; 267:114217. [PMID: 37127074 DOI: 10.1016/j.physbeh.2023.114217] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 04/14/2023] [Accepted: 04/28/2023] [Indexed: 05/03/2023]
Abstract
This study investigated the acute performance, physiological, and perceptual changes during repeated sprint exercise (RSE) under normobaric hypoxia and with blood flow restriction (BFR). Fourteen active males completed standardized RSE (6 × 10s cycling sprints with 30s passive rest) in three randomized conditions: under normobaric hypoxia (FiO2∼14.4%, HYP), normoxia (FiO2∼20.9%, SHAM), and with BFR (40% arterial occlusion pressure). The percentage decrement score of power output (Sdec) was used to quantify motor performance fatigue. During RSE, muscle oxygenation and activity of the right quadriceps were measured. Perceived motor fatigue, physical strain, affective valence, and arousal were queried after each sprint. Blood lactate concentration (BLC) and peripheral oxygenation (SpO2) were measured before and after RSE. Sdec was greater in HYP and BFR compared to SHAM (p≤0.008). BFR decreased mean power output (p<0.001) and muscle activity (p=0.027) compared to SHAM. Muscle oxygenation was lower in BFR during each rest (p≤0.005) and in HYP during rest 4 (p=0.006) compared to SHAM. HYP increased BLC and decreased SpO2 compared to BFR (p<0.001) and SHAM (p=0.002). There were no differences between conditions for any rating scale (p≥0.060). HYP and BFR increased motor performance fatigue but with different physiological responses, whereas perceptual responses were unaffected during RSE.
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Affiliation(s)
- Tom Behrendt
- Department of Sport Science, Institute III, Otto-von-Guericke University Magdeburg, 39104 Magdeburg, Germany.
| | - Robert Bielitzki
- Department of Sport Science, Institute III, Otto-von-Guericke University Magdeburg, 39104 Magdeburg, Germany
| | - Martin Behrens
- Department of Sport Science, Institute III, Otto-von-Guericke University Magdeburg, 39104 Magdeburg, Germany
| | - Lutz Schega
- Department of Sport Science, Institute III, Otto-von-Guericke University Magdeburg, 39104 Magdeburg, Germany
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Ušaj A, Sotiridis A, Debevec T. Cardio-Respiratory and Muscle Oxygenation Responses to Submaximal and Maximal Exercise in Normobaric Hypoxia: Comparison between Children and Adults. BIOLOGY 2023; 12:biology12030457. [PMID: 36979149 PMCID: PMC10044758 DOI: 10.3390/biology12030457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 03/10/2023] [Accepted: 03/13/2023] [Indexed: 03/18/2023]
Abstract
As differential physiological responses to hypoxic exercise between adults and children remain poorly understood, we aimed to comprehensively characterise cardiorespiratory and muscle oxygenation responses to submaximal and maximal exercise in normobaric hypoxia between the two groups. Following familiarisation, fifteen children (Age = 9 ± 1 years) and fifteen adults (Age = 22 ± 2 years) completed two graded cycling exercise sessions to exhaustion in a randomized and single-blind manner in normoxia (NOR; FiO2 = 20.9) and normobaric hypoxia (HYP; FiO2 = 13.0) exercises conditions. Age-specific workload increments were 25 W·3 min−1 for children and 40 W·3 min−1 for adults. Gas exchange and vastus lateralis oxygenation parameters were measured continuously via metabolic cart and near-infrared spectroscopy, respectively. Hypoxia provoked significant decreases in maximal power output PMAX (children = 29%; adults 16% (F = 39.3; p < 0.01)) and power output at the gas exchange threshold (children = 10%; adults:18% (F = 8.08; p = 0.01)) in both groups. Comparable changes were noted in most respiratory and gas exchange parameters at similar power outputs between groups. Children, however, demonstrated, lower PETCO2 throughout the test at similar power outputs and during the maintenance of V˙CO2 at the maximal power output. These data indicate that, while most cardiorespiratory responses to acute hypoxic exercise are comparable between children and adults, there exist age-related differential responses in select respiratory and muscle oxygenation parameters.
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Affiliation(s)
- Anton Ušaj
- Faculty of Sport, University of Ljubljana, SI-1000 Ljubljana, Slovenia
| | - Alexandros Sotiridis
- School of Physical Education and Sport Science, National and Kapodistrian University of Athens, 115 27 Athens, Greece
- Department of Automatics, Biocybernetics and Robotics, Jozef Stefan Institute, SI-1000 Ljubljana, Slovenia
| | - Tadej Debevec
- Faculty of Sport, University of Ljubljana, SI-1000 Ljubljana, Slovenia
- Department of Automatics, Biocybernetics and Robotics, Jozef Stefan Institute, SI-1000 Ljubljana, Slovenia
- Correspondence:
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Samaja M, Ottolenghi S. The Oxygen Cascade from Atmosphere to Mitochondria as a Tool to Understand the (Mal)adaptation to Hypoxia. Int J Mol Sci 2023; 24:ijms24043670. [PMID: 36835089 PMCID: PMC9960749 DOI: 10.3390/ijms24043670] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 02/05/2023] [Accepted: 02/09/2023] [Indexed: 02/15/2023] Open
Abstract
Hypoxia is a life-threatening challenge for about 1% of the world population, as well as a contributor to high morbidity and mortality scores in patients affected by various cardiopulmonary, hematological, and circulatory diseases. However, the adaptation to hypoxia represents a failure for a relevant portion of the cases as the pathways of potential adaptation often conflict with well-being and generate diseases that in certain areas of the world still afflict up to one-third of the populations living at altitude. To help understand the mechanisms of adaptation and maladaptation, this review examines the various steps of the oxygen cascade from the atmosphere to the mitochondria distinguishing the patterns related to physiological (i.e., due to altitude) and pathological (i.e., due to a pre-existing disease) hypoxia. The aim is to assess the ability of humans to adapt to hypoxia in a multidisciplinary approach that correlates the function of genes, molecules, and cells with the physiologic and pathological outcomes. We conclude that, in most cases, it is not hypoxia by itself that generates diseases, but rather the attempts to adapt to the hypoxia condition. This underlies the paradigm shift that when adaptation to hypoxia becomes excessive, it translates into maladaptation.
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Affiliation(s)
- Michele Samaja
- MAGI GROUP, San Felice del Benaco, 25010 Brescia, Italy
- Correspondence:
| | - Sara Ottolenghi
- School of Medicine and Surgery, University of Milano Bicocca, 20126 Milan, Italy
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Circulating nitrate-nitrite reduces oxygen uptake for improving resistance exercise performance after rest time in well-trained CrossFit athletes. Sci Rep 2022; 12:9671. [PMID: 35690665 PMCID: PMC9188609 DOI: 10.1038/s41598-022-13786-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 05/27/2022] [Indexed: 12/21/2022] Open
Abstract
This study aimed to determine the effects of circulating nitrate plus nitrite (NOx) concentrations on resistance exercise performance, VO2 and biomarkers of muscle damage. Eleven well-trained male CrossFit athletes (29.2 ± 3.7 years, 78.9 ± 5.4 kg, 175.1 ± 6.3 cm) carried out a resistance exercise test after drinking 140 mL of beetroot juice (BJ) or placebo. The test consisted of repeating the same resistance exercise routine twice: wall ball shots plus full back squat with 3-min rest (1st routine) or without rest (2nd routine) between the two exercises. Higher NOx plasma levels were verified after BJ than placebo in the pretest and post-test (p < 0.001). A higher number of repetitions was observed after BJ intake compared to placebo in the full back squat exercise during the first routine (p = 0.004). A significantly reduced VO2 was detected after BJ intake compared to placebo during rest and full back squat execution in the first routine (p < 0.05). Plasma myoglobin concentrations were significantly increased with BJ compared to placebo (p = 0.036). These results showed that plasma NOx levels reduced VO2 after BJ intake during rest time. These reduced VO2 was a key factor for improving full back squat performance during the first routine.
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Park HY, Kim SW, Jung WS, Kim J, Lim K. Hypoxic Therapy as a New Therapeutic Modality for Cardiovascular Benefit: A Mini Review. Rev Cardiovasc Med 2022; 23:161. [PMID: 39077598 PMCID: PMC11273974 DOI: 10.31083/j.rcm2305161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 03/11/2022] [Accepted: 03/18/2022] [Indexed: 07/31/2024] Open
Abstract
Cardiovascular diseases (CVDs) are recognized as one of the major causes of morbidity and mortality worldwide. Generally, most CVDs can be prevented by addressing behavioral risk factors, including smoking, unhealthy diet and obesity, lack of physical activity, and alcohol abuse. Therefore, it is important to have a healthy lifestyle by performing regular physical activity to improve cardiovascular health and diseases. However, a majority of adults worldwide do not meet the minimum recommendations for regular aerobic exercise, and overweight and obesity ratio continues to rise. In addition, obese individuals, with a high prevalence of CVDs, have a lower participation rate for exercise because of the strain on the musculoskeletal system. Hypoxic therapy, including exposure or exercise intervention under hypoxia, has been utilized as a new therapeutic modality for cardiovascular benefit and amelioration of CVDs. Hypoxic therapy shows various physiological and pathophysiological properties, including increased appetite suppression and dietary intake reduction, increased energy consumption, improved glycogen storage, enhanced fatty acid oxidation, improved myocardial angiogenesis or ventricular remodeling, augmentation of blood flow within the skeletal muscle vascular beds, and reduction of the burden on the musculoskeletal system making it applicable to patients with CVDs and obesity with attenuated cardiovascular function. In particular, hypoxic therapy is very effective in improving cardiovascular benefits and preventing CVDs by enhancing arterial function, vascular endothelial function, and hemorheological properties. These observations indicate that hypoxic therapy may be an important and essential strategy for improving cardiovascular health and reducing cardiovascular morbidity and mortality.
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Affiliation(s)
- Hun-Young Park
- Department of Sports Medicine and Science, Graduate School, Konkuk University, 05029 Seoul, Republic of Korea
- Physical Activity and Performance Institute (PAPI), Konkuk University, 05029 Seoul, Republic of Korea
| | - Sung-Woo Kim
- Department of Sports Medicine and Science, Graduate School, Konkuk University, 05029 Seoul, Republic of Korea
| | - Won-Sang Jung
- Department of Sports Medicine and Science, Graduate School, Konkuk University, 05029 Seoul, Republic of Korea
| | - Jisu Kim
- Department of Sports Medicine and Science, Graduate School, Konkuk University, 05029 Seoul, Republic of Korea
- Physical Activity and Performance Institute (PAPI), Konkuk University, 05029 Seoul, Republic of Korea
| | - Kiwon Lim
- Department of Sports Medicine and Science, Graduate School, Konkuk University, 05029 Seoul, Republic of Korea
- Physical Activity and Performance Institute (PAPI), Konkuk University, 05029 Seoul, Republic of Korea
- Department of Physical Education, Konkuk University, 05029 Seoul, Republic of Korea
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A century of exercise physiology: key concepts on coupling respiratory oxygen flow to muscle energy demand during exercise. Eur J Appl Physiol 2022; 122:1317-1365. [PMID: 35217911 PMCID: PMC9132876 DOI: 10.1007/s00421-022-04901-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 01/25/2022] [Indexed: 12/26/2022]
Abstract
After a short historical account, and a discussion of Hill and Meyerhof’s theory of the energetics of muscular exercise, we analyse steady-state rest and exercise as the condition wherein coupling of respiration to metabolism is most perfect. The quantitative relationships show that the homeostatic equilibrium, centred around arterial pH of 7.4 and arterial carbon dioxide partial pressure of 40 mmHg, is attained when the ratio of alveolar ventilation to carbon dioxide flow (\documentclass[12pt]{minimal}
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\begin{document}$${\dot{V}}_{A}/{\dot{V}}_{R}{CO}_{2}$$\end{document}V˙A/V˙RCO2) is − 21.6. Several combinations, exploited during exercise, of pertinent respiratory variables are compatible with this equilibrium, allowing adjustment of oxygen flow to oxygen demand without its alteration. During exercise transients, the balance is broken, but the coupling of respiration to metabolism is preserved when, as during moderate exercise, the respiratory system responds faster than the metabolic pathways. At higher exercise intensities, early blood lactate accumulation suggests that the coupling of respiration to metabolism is transiently broken, to be re-established when, at steady state, blood lactate stabilizes at higher levels than resting. In the severe exercise domain, coupling cannot be re-established, so that anaerobic lactic metabolism also contributes to sustain energy demand, lactate concentration goes up and arterial pH falls continuously. The \documentclass[12pt]{minimal}
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\begin{document}$${\dot{V}}_{A}/{\dot{V}}_{R}{CO}_{2}$$\end{document}V˙A/V˙RCO2 decreases below − 21.6, because of ensuing hyperventilation, while lactate keeps being accumulated, so that exercise is rapidly interrupted. The most extreme rupture of the homeostatic equilibrium occurs during breath-holding, because oxygen flow from ambient air to mitochondria is interrupted. No coupling at all is possible between respiration and metabolism in this case.
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Webb KL, Dominelli PB, Baker SE, Klassen SA, Joyner MJ, Senefeld JW, Wiggins CC. Influence of High Hemoglobin-Oxygen Affinity on Humans During Hypoxia. Front Physiol 2022; 12:763933. [PMID: 35095551 PMCID: PMC8795792 DOI: 10.3389/fphys.2021.763933] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 12/22/2021] [Indexed: 01/11/2023] Open
Abstract
Humans elicit a robust series of physiological responses to maintain adequate oxygen delivery during hypoxia, including a transient reduction in hemoglobin-oxygen (Hb-O2) affinity. However, high Hb-O2 affinity has been identified as a beneficial adaptation in several species that have been exposed to high altitude for generations. The observed differences in Hb-O2 affinity between humans and species adapted to high altitude pose a central question: is higher or lower Hb-O2 affinity in humans more advantageous when O2 availability is limited? Humans with genetic mutations in hemoglobin structure resulting in high Hb-O2 affinity have shown attenuated cardiorespiratory adjustments during hypoxia both at rest and during exercise, providing unique insight into this central question. Therefore, the purpose of this review is to examine the influence of high Hb-O2 affinity during hypoxia through comparison of cardiovascular and respiratory adjustments elicited by humans with high Hb-O2 affinity compared to those with normal Hb-O2 affinity.
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Affiliation(s)
- Kevin L. Webb
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN, United States
| | | | - Sarah E. Baker
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN, United States
| | - Stephen A. Klassen
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN, United States
- Department of Kinesiology, Brock University, St. Catharines, ON, Canada
| | - Michael J. Joyner
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN, United States
| | - Jonathon W. Senefeld
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN, United States
| | - Chad C. Wiggins
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN, United States
- *Correspondence: Chad C. Wiggins,
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11
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Dech S, Bittmann FN, Schaefer LV. Muscle Oxygenation Level Might Trigger the Regulation of Capillary Venous Blood Filling during Fatiguing Isometric Muscle Actions. Diagnostics (Basel) 2021; 11:1973. [PMID: 34829320 PMCID: PMC8621102 DOI: 10.3390/diagnostics11111973] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 10/19/2021] [Accepted: 10/19/2021] [Indexed: 01/14/2023] Open
Abstract
The regulation of oxygen and blood supply during isometric muscle actions is still unclear. Recently, two behavioral types of oxygen saturation (SvO2) and relative hemoglobin amount (rHb) in venous microvessels were described during a fatiguing holding isometric muscle action (HIMA) (type I: nearly parallel behavior of SvO2 and rHb; type II: partly inverse behavior). The study aimed to ascertain an explanation of these two regulative behaviors. Twelve subjects performed one fatiguing HIMA trial with each arm by weight holding at 60% of the maximal voluntary isometric contraction (MVIC) in a 90° elbow flexion. Six subjects additionally executed one fatiguing PIMA trial by pulling on an immovable resistance with 60% of the MVIC with each side and same position. Both regulative types mentioned were found during HIMA (I: n = 7, II: n = 17) and PIMA (I: n = 3, II: n = 9). During the fatiguing measurements, rHb decreased initially and started to increase in type II at an average SvO2-level of 58.75 ± 2.14%. In type I, SvO2 never reached that specific value during loading. This might indicate the existence of a threshold around 59% which seems to trigger the increase in rHb and could explain the two behavioral types. An approach is discussed to meet the apparent incompatibility of an increased capillary blood filling (rHb) despite high intramuscular pressures which were found by other research groups during isometric muscle actions.
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Affiliation(s)
- Silas Dech
- Devision of Regulative Physiology and Prevention, Department of Sports and Health Sciences, University of Potsdam, 14476 Potsdam, Germany; (F.N.B.); (L.V.S.)
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12
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Lavier J, Beaumann M, Menétrey S, Bouzourène K, Rosenblatt‐Velin N, Pialoux V, Mazzolai L, Peyter A, Pellegrin M, Millet GP. High-intensity exercise in hypoxia improves endothelial function via increased nitric oxide bioavailability in C57BL/6 mice. Acta Physiol (Oxf) 2021; 233:e13700. [PMID: 34089562 PMCID: PMC8518730 DOI: 10.1111/apha.13700] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 06/01/2021] [Accepted: 06/01/2021] [Indexed: 02/04/2023]
Abstract
AIM The optimal exercise intensity to improve endothelial function remains unclear, as well as whether the addition of hypoxia could potentiate this function. Therefore, the aim of this study was to compare the effects of different exercise intensities in normoxia and hypoxia on vascular reactivity and nitric oxide (NO) bioavailability in mice. METHODS C57BL/6 mice underwent treadmill running three times per week, for 4 weeks at either low, maximal or supramaximal intensity in normoxia or hypoxia (inspire oxygen fraction = 0.13). Vascular reactivity and expression of genes and proteins involved in NO production/bioavailability were assessed in aorta using isolated vessel tension experiments, RT-qPCR and western blot, respectively. Circulating NO metabolites and pro-/antioxidant markers were measured. RESULTS Hypoxic exercise improved both acetylcholine-induced vasorelaxation and phenylephrine-induced vasoconstriction compared to normoxic exercise, independently of intensity. In hypoxia, a higher acetylcholine-induced vasorelaxation was observed with high intensities (supramaximal and maximal) compared to low intensity. Exercise protocols modulated endothelial nitric oxide synthase (eNOS) and α1-adrenergic receptor (α1 -AR) mRNA level, but not superoxide dismutase 3 (SOD3) and p47phox. No significant differences were observed for protein expression of α1 -AR, total eNOS, phosphorylated eNOS, SOD isoforms and p47phox. However, plasma SOD and catalase activities were significantly increased in hypoxic supramaximal compared to hypoxic low intensity, while concentration of nitrotyrosine significantly decreased. The latter was also observed in hypoxic maximal and supramaximal compared to the same intensities in normoxia. CONCLUSION Hypoxic high-intensity exercise increases NO bioavailability and improves vascular function, opening promising clinical perspectives for cardiovascular disease prevention.
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Affiliation(s)
- Jessica Lavier
- Division of Angiology, Heart and Vessel DepartmentLausanne University Hospital (CHUV)LausanneSwitzerland
- Institute of Sport SciencesUniversity of LausanneLausanneSwitzerland
| | - Manon Beaumann
- Neonatal Research LaboratoryClinic of NeonatologyDepartment Woman‐Mother‐ChildLausanne University Hospital (CHUV)LausanneSwitzerland
| | - Steeve Menétrey
- Neonatal Research LaboratoryClinic of NeonatologyDepartment Woman‐Mother‐ChildLausanne University Hospital (CHUV)LausanneSwitzerland
| | - Karima Bouzourène
- Division of Angiology, Heart and Vessel DepartmentLausanne University Hospital (CHUV)LausanneSwitzerland
| | - Nathalie Rosenblatt‐Velin
- Division of Angiology, Heart and Vessel DepartmentLausanne University Hospital (CHUV)LausanneSwitzerland
| | - Vincent Pialoux
- Inter‐University Laboratory of Human Movement Biology EA7424University of LyonVilleurbanneFrance
| | - Lucia Mazzolai
- Division of Angiology, Heart and Vessel DepartmentLausanne University Hospital (CHUV)LausanneSwitzerland
| | - Anne‐Christine Peyter
- Neonatal Research LaboratoryClinic of NeonatologyDepartment Woman‐Mother‐ChildLausanne University Hospital (CHUV)LausanneSwitzerland
| | - Maxime Pellegrin
- Division of Angiology, Heart and Vessel DepartmentLausanne University Hospital (CHUV)LausanneSwitzerland
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13
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Lemieux P, Birot O. Altitude, Exercise, and Skeletal Muscle Angio-Adaptive Responses to Hypoxia: A Complex Story. Front Physiol 2021; 12:735557. [PMID: 34552509 PMCID: PMC8450406 DOI: 10.3389/fphys.2021.735557] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 08/16/2021] [Indexed: 12/18/2022] Open
Abstract
Hypoxia, defined as a reduced oxygen availability, can be observed in many tissues in response to various physiological and pathological conditions. As a hallmark of the altitude environment, ambient hypoxia results from a drop in the oxygen pressure in the atmosphere with elevation. A hypoxic stress can also occur at the cellular level when the oxygen supply through the local microcirculation cannot match the cells’ metabolic needs. This has been suggested in contracting skeletal myofibers during physical exercise. Regardless of its origin, ambient or exercise-induced, muscle hypoxia triggers complex angio-adaptive responses in the skeletal muscle tissue. These can result in the expression of a plethora of angio-adaptive molecules, ultimately leading to the growth, stabilization, or regression of muscle capillaries. This remarkable plasticity of the capillary network is referred to as angio-adaptation. It can alter the capillary-to-myofiber interface, which represent an important determinant of skeletal muscle function. These angio-adaptive molecules can also be released in the circulation as myokines to act on distant tissues. This review addresses the respective and combined potency of ambient hypoxia and exercise to generate a cellular hypoxic stress in skeletal muscle. The major skeletal muscle angio-adaptive responses to hypoxia so far described in this context will be discussed, including existing controversies in the field. Finally, this review will highlight the molecular complexity of the skeletal muscle angio-adaptive response to hypoxia and identify current gaps of knowledges in this field of exercise and environmental physiology.
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Affiliation(s)
- Pierre Lemieux
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, ON, Canada
| | - Olivier Birot
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, ON, Canada
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14
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Azevedo RDA, J E BS, Inglis EC, Iannetta D, Murias JM. Hypoxia equally reduces the respiratory compensation point and the NIRS-derived [HHb] breakpoint during a ramp-incremental test in young active males. Physiol Rep 2021; 8:e14478. [PMID: 32592338 PMCID: PMC7319946 DOI: 10.14814/phy2.14478] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 05/13/2020] [Indexed: 12/20/2022] Open
Abstract
This study investigated the effect of reduced inspired fraction of O2 (FiO2) in the correspondence between the respiratory compensation point (RCP) and the breakpoint in the near‐infrared spectroscopy‐derived deoxygenated hemoglobin signal ([HHb]bp) during a ramp‐incremental (RI) test to exhaustion. Eleven young males performed, on two separated occasions, a RI test either in normoxia (NORM, FiO2 = 20.9%) or hypoxia (HYPO, FiO2 = 16%). Oxygen uptake (
V˙O2), and [HHb] signal from the vastus lateralis muscle were continuously measured. Peak
V˙O2 (2.98 ± 0.36 vs. 3.39 ± 0.26 L min−1) and PO (282 ± 29 vs. 310 ± 19 W) were lower in HYPO compared to NORM condition, respectively. The
V˙O2 and PO associated with RCP and [HHb]bp were lower in HYPO (2.35 ± 0.24 and 2.34 ± 0.26 L min−1; 198 ± 37 and 197 ± 30 W, respectively) when compared to NORM (2.75 ± 0.26 and 2.75 ± 0.28 L min−1; 244 ± 29 and 241 ± 28 W, respectively) (p < .05). Within the same condition, the
V˙O2 and PO associated with RCP and [HHb]bp were not different (p > .05). Bland–Altman plots mean average errors between RCP and [HHb]bp were not different from zero in HYPO (0.01 L min−1 and 1.1 W) and NORM (0.00 L min−1 and 3.6 W) conditions. The intra‐individual changes between thresholds associated with
V˙O2 and PO in HYPO from NORM were strongly correlated (r = .626 and 0.752, p < .05). Therefore, breathing a lower FiO2 during a RI test resulted in proportional reduction in the RCP and the [HHb]bp in terms of
V˙O2 and PO, which further supports the notion that these physiological responses may arise from similar metabolic changes reflecting a common phenomenon.
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Affiliation(s)
| | - Béjar Saona J E
- Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
| | | | - Danilo Iannetta
- Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
| | - Juan M Murias
- Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
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15
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Bock JM, Hughes WE, Ueda K, Feider AJ, Hanada S, Casey DP. Glycemic management is inversely related to skeletal muscle microvascular endothelial function in patients with type 2 diabetes. Physiol Rep 2021; 9:e14764. [PMID: 33660935 PMCID: PMC7931618 DOI: 10.14814/phy2.14764] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 01/20/2021] [Accepted: 01/22/2021] [Indexed: 11/24/2022] Open
Abstract
Microvascular endothelial dysfunction precipitates cardiovascular disease mortality in patients with type 2 diabetes mellitus (T2DM). However, the relationship between glycemic management and microvascular endothelial function of these patients remains ill defined. We investigated the association between skeletal muscle microvascular endothelial function with glycemic management (HbA1c) and responses to an oral glucose challenge (OGTT) in 30 patients with T2DM (59 ± 9 years, 31.2 ± 5.1 kg/m2 , HbA1c = 7.3 ± 1.3%). On study day 1, microvascular endothelial function was quantified as the increase (Δ from rest) in forearm vascular conductance (FVC, ml/min/100 mmHg) during intra-arterial acetylcholine infusion at 4.0 and 8.0 μg/dl forearm volume/min (ACh4 and ACh8, respectively). [Glucose] and [insulin] were measured in a fasted state as well as following a 75 g OGTT on a second day with an additional fasting blood sample collected to measure HbA1c. FVC increased (Δ) 221 ± 118 and 251 ± 144 ml/min/100 mm Hg during ACh4 and ACh8 trials, respectively (p < 0.05 between doses). [Glucose] and [insulin] increased at the 1-h time point, relative to fasting levels, and remained elevated 2 h post-consumption (p < 0.05 for both variables and time points). [Glucose] nor [insulin], fasting or during the OGTT, were associated with ΔFVC during ACh4 or ACh8, respectively (p = 0.11-0.86), although HbA1c was inversely related (r = -0.47 and -0.46, respectively, p < 0.01 for both). Patients whose HbA1c met the ADA's therapeutic target of ≤7.0% had greater ΔFVC to ACh4 (272 ± 147 vs. 182 ± 74 ml/100 mm Hg/min) and ACh8 (324 ± 171 vs. 196 ± 90 ml/100 mm Hg/min, p < 0.05 for both trials) compared to those with >7.0%, respectively. Our data show glycemic management is related to acetylcholine-mediated vasodilation (e.g., microvascular endothelial function) in skeletal muscle of patients with T2DM.
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Affiliation(s)
- Joshua M Bock
- Department of Physical Therapy & Rehabilitation Science, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - William E Hughes
- Department of Physical Therapy & Rehabilitation Science, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Kenichi Ueda
- Department of Anesthesia, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Andrew J Feider
- Department of Anesthesia, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Satoshi Hanada
- Department of Anesthesia, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Darren P Casey
- Department of Physical Therapy & Rehabilitation Science, Carver College of Medicine, University of Iowa, Iowa City, IA, USA.,Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA, USA.,Fraternal Order of Eagles Diabetes Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
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16
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Poole DC, Behnke BJ, Musch TI. The role of vascular function on exercise capacity in health and disease. J Physiol 2021; 599:889-910. [PMID: 31977068 PMCID: PMC7874303 DOI: 10.1113/jp278931] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 12/10/2019] [Indexed: 12/16/2022] Open
Abstract
Three sentinel parameters of aerobic performance are the maximal oxygen uptake ( V ̇ O 2 max ), critical power (CP) and speed of the V ̇ O 2 kinetics following exercise onset. Of these, the latter is, perhaps, the cardinal test of integrated function along the O2 transport pathway from lungs to skeletal muscle mitochondria. Fast V ̇ O 2 kinetics demands that the cardiovascular system distributes exercise-induced blood flow elevations among and within those vascular beds subserving the contracting muscle(s). Ideally, this process must occur at least as rapidly as mitochondrial metabolism elevates V ̇ O 2 . Chronic disease and ageing create an O2 delivery (i.e. blood flow × arterial [O2 ], Q ̇ O 2 ) dependency that slows V ̇ O 2 kinetics, decreasing CP and V ̇ O 2 max , increasing the O2 deficit and sowing the seeds of exercise intolerance. Exercise training, in contrast, does the opposite. Within the context of these three parameters (see Graphical Abstract), this brief review examines the training-induced plasticity of key elements in the O2 transport pathway. It asks how structural and functional vascular adaptations accelerate and redistribute muscle Q ̇ O 2 and thus defend microvascular O2 partial pressures and capillary blood-myocyte O2 diffusion across a ∼100-fold range of muscle V ̇ O 2 values. Recent discoveries, especially in the muscle microcirculation and Q ̇ O 2 -to- V ̇ O 2 heterogeneity, are integrated with the O2 transport pathway to appreciate how local and systemic vascular control helps defend V ̇ O 2 kinetics and determine CP and V ̇ O 2 max in health and how vascular dysfunction in disease predicates exercise intolerance. Finally, the latest evidence that nitrate supplementation improves vascular and therefore aerobic function in health and disease is presented.
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Affiliation(s)
- David C Poole
- Departments of Kinesiology and Anatomy and Physiology, Kansas State University, Manhattan, KS, 66506, USA
| | - Brad J Behnke
- Departments of Kinesiology and Anatomy and Physiology, Kansas State University, Manhattan, KS, 66506, USA
| | - Timothy I Musch
- Departments of Kinesiology and Anatomy and Physiology, Kansas State University, Manhattan, KS, 66506, USA
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17
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Fentanyl impairs but ketamine preserves the microcirculatory response to hemorrhage. J Trauma Acute Care Surg 2021; 89:S93-S99. [PMID: 32044869 DOI: 10.1097/ta.0000000000002604] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
BACKGROUND Peripheral vasoconstriction is the most critical compensating mechanism following hemorrhage to maintain blood pressure. On the battlefield, ketamine rather than opioids is recommended for pain management in case of hemorrhage, but effects of analgesics on compensatory vasoconstriction are not defined. We hypothesized that fentanyl impairs but ketamine preserves the peripheral vasoconstriction and blood pressure compensation following hemorrhage. METHOD Sprague-Dawley rats (11-13 weeks) were randomly assigned to control (saline vehicle), fentanyl, or ketamine-treated groups with or without hemorrhage (n = 8 or 9 for each group). Rats were anesthetized with Inactin (i.p. 10 mg/100 g), and the spinotrapezius muscles were prepared for microcirculatory observation. Arteriolar arcades were observed with a Nikon microscope, and vessel images and arteriolar diameters were recorded by using Nikon NIS Elements Imaging Software (Nikon Instruments Inc. NY). After baseline perimeters were recorded, the arterioles were topically challenged with saline, fentanyl, or ketamine at concentrations relevant to intravenous analgesic doses to determine direct vasoactive effects. After arteriolar diameters returned to baseline, 30% of total blood volume was removed in 25 minutes. Ten minutes after hemorrhage, rats were intravenously injected with an analgesic dose of fentanyl (0.6 μg/100 g), ketamine (0.3 mg/100 g), or a comparable volume of saline. For each drug or vehicle administration, the total volume injected was 0.1 mL/100 g. Blood pressure, heart rate, and arteriolar responses were monitored for 40 minutes. RESULTS Topical fentanyl-induced vasodilation (17 ± 2%), but ketamine caused vasoconstriction (-15 ± 4%, p < 0.01). Following hemorrhage, intravenous ketamine did not affect blood pressure or respiratory rate, while fentanyl induced a slight and transient (<5 minutes, p = 0.03 vs. saline group) decrease in blood pressure, with a profound and prolonged suppression in respiratory rate (>10 minutes, with a peak inhibition of 57 ± 8% of baseline, p < 0.01). The compensatory vasoconstriction observed after hemorrhage was not affected by ketamine treatment. However, after fentanyl injection, although changes in blood pressure were transiently present, arteriolar constriction to hemorrhage was absent and replaced with a sustained vasodilation (78 ± 25% to 36 ± 22% of baseline during the 40 minutes after injection, p < 0.01). CONCLUSION Ketamine affects neither systemic nor microcirculatory compensatory responses to hemorrhage, providing preclinical evidence that ketamine may help attenuate adverse physiological consequences associated with opioids following traumatic hemorrhage. Microcirculatory responses are more sensitive than systemic response for evaluation of hemodynamic stability during procedures associated with pain management.
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18
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Gifford JR, Hanson BE, Proffit M, Wallace T, Kofoed J, Griffin G, Hanson M. Indices of leg resistance artery function are independently related to cycling V̇O 2 max. Physiol Rep 2020; 8:e14551. [PMID: 32812353 PMCID: PMC7435036 DOI: 10.14814/phy2.14551] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 07/26/2020] [Indexed: 12/30/2022] Open
Abstract
PURPOSE While maximum blood flow influences one's maximum rate of oxygen consumption (V̇O2 max), with so many indices of vascular function, it is still unclear if vascular function is related to V̇O2 max in healthy, young adults. The purpose of this study was to determine if several common vascular tests of conduit artery and resistance artery function provide similar information about vascular function and the relationship between vascular function and V̇O2 max. METHODS Twenty-two healthy adults completed multiple assessments of leg vascular function, including flow-mediated dilation (FMD), reactive hyperemia (RH), passive leg movement (PLM), and rapid onset vasodilation (ROV). V̇O2 max was assessed with a graded exercise test on a cycle ergometer. RESULTS Indices associated with resistance artery function (e.g., peak flow during RH, PLM, and ROV) were generally related to each other (r = 0.47-77, p < .05), while indices derived from FMD were unrelated to other tests (p < .05). Absolute V̇O2 max (r = 0.57-0.73, p < .05) and mass-specific V̇O2 max (r = 0.41-0.46, p < .05) were related to indices of resistance artery function, even when controlling for factors like body mass and sex. FMD was only related to mass-specific V̇O2 max after statistically controlling for baseline artery diameter (r = 0.44, p < .05). CONCLUSION Indices of leg resistance artery function (e.g., peak flow during RH, PLM, and ROV) relate well to each other and account for ~30% of the variance in V̇O2 max not accounted for by other factors, like body mass and sex. Vascular interventions should focus on improving indices of resistance artery function, not conduit artery function, when seeking to improve exercise capacity.
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Affiliation(s)
- Jayson R. Gifford
- Department of Exercise SciencesBrigham Young UniversityProvoUTUSA
- Program of GerontologyBrigham Young UniversityProvoUTUSA
| | - Brady E. Hanson
- Department of Exercise SciencesBrigham Young UniversityProvoUTUSA
| | - Meagan Proffit
- Department of Exercise SciencesBrigham Young UniversityProvoUTUSA
- Program of GerontologyBrigham Young UniversityProvoUTUSA
| | - Taysom Wallace
- Department of Exercise SciencesBrigham Young UniversityProvoUTUSA
| | - Jason Kofoed
- Department of Exercise SciencesBrigham Young UniversityProvoUTUSA
| | - Garrett Griffin
- Department of Exercise SciencesBrigham Young UniversityProvoUTUSA
| | - Melina Hanson
- Department of Exercise SciencesBrigham Young UniversityProvoUTUSA
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19
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Du X, Girard O, Fan RY, Ma F. Effects of Active and Passive Hypoxic Conditioning for 6 Weeks at Different Altitudes on Blood Lipids, Leptin, and Weight in Rats. High Alt Med Biol 2020; 21:243-248. [PMID: 32486854 DOI: 10.1089/ham.2020.0003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Du, Xia, Olivier Girard, Rong yun Fan, and Fuhai Ma. Effects of active and passive hypoxic conditioning for 6 weeks at different altitudes on blood lipids, leptin, and weight in rats. High Alt Med Biol. 21:243-248, 2020. Objective: To compare the effects of 6 weeks of passive and active hypoxia exposure at different altitudes on lipid metabolism, leptin, and weight in rats. Materials and Methods: Eighty 9-week-old male Wistar rats were assigned to either non-exercise or exercise groups. Each group was subdivided into four categories (n = 10) based on hypoxic conditions: 0, 2200, 2200 + 3500, and 3500 m. Rats in the exercise group trained on a treadmill at a speed of 20-22 m/min (0° incline) for 90 minutes, 5 days per week for 6 weeks. Serum lipid and leptin levels and weight were measured following the intervention. Results: Total cholesterol (-8.2% ± 3.5%), low-density lipoproteins (-29.8% ± 8.1%), and triglyceride (TG) levels (-17.2% ± 3.8%) were lower, and high-density lipoproteins (+7.4% ± 4.0%) higher, in exercise versus non-exercise groups (all p < 0.001), independent of condition. TG levels were lower at altitude (-13.0% ± 27.3%, -10.9% ± 24.3%, and -9.2% ± 20.9% at 2200, 2200 + 3500, and 3500 m, respectively) compared to 0 m (p < 0.001). Hypoxic exposure decreased leptin with lower values at 2200 + 3500 m and 3500 m compared to 0 m (p < 0.05). Weight was lower in exercise than non-exercise groups (-8.2% ± 21.0%; p < 0.001), and at altitude (-2.7% ± 2.6%, -5.5% ± 3.7%, and -5.7% ± 2.7% at 2200, 2200 + 3500, and 3500 m, respectively) compared to 0 m. Conclusion: Regular aerobic exercise led to more favorable responses for lipid metabolism and weight control than the oxygenation conditions the animals are in.
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Affiliation(s)
- Xia Du
- Qinghai Provincial Sports Bureau, Qinghai Institute of Sports Science, Xi Ning, China.,China National Sports Bureau, Key Lab of Plateau Training in China General Administration of Sport, Xi Ning, China.,Qinghai Provincial Department of Science and Technology, Excellent Key Lab of Plateau Physical Education in Qinghai Province, Xi Ning, China
| | - Olivier Girard
- School of Human Sciences, Exercise and Sport Science, The University of Western Australia, Crawley, Australia
| | - Rong Yun Fan
- Qinghai Provincial Sports Bureau, Qinghai Institute of Sports Science, Xi Ning, China.,China National Sports Bureau, Key Lab of Plateau Training in China General Administration of Sport, Xi Ning, China.,Qinghai Provincial Department of Science and Technology, Excellent Key Lab of Plateau Physical Education in Qinghai Province, Xi Ning, China
| | - Fuhai Ma
- Qinghai Provincial Sports Bureau, Qinghai Institute of Sports Science, Xi Ning, China.,China National Sports Bureau, Key Lab of Plateau Training in China General Administration of Sport, Xi Ning, China.,Qinghai Provincial Department of Science and Technology, Excellent Key Lab of Plateau Physical Education in Qinghai Province, Xi Ning, China
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20
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Nemeth Z, Hildebrandt E, Ryan MJ, Granger JP, Drummond HA. Pressure-induced constriction of the middle cerebral artery is abolished in TrpC6 knockout mice. Am J Physiol Heart Circ Physiol 2020; 319:H42-H50. [PMID: 32412783 DOI: 10.1152/ajpheart.00126.2020] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Pressure-induced constriction (PIC) is an inherent response of small arteries and arterioles in which increases in intraluminal pressure evoke vasoconstriction. It is a critical mechanism of blood flow autoregulation in the kidney and brain. Degenerin (Deg) and transient receptor potential (Trp) protein families have been implicated in transduction of PIC because of evolutionary links to mechanosensing in the nematode and fly. While TrpC6 has been suggested to contribute to PIC signaling, direct supporting evidence is contradictory. Therefore, the aim of this study was to determine the importance of TrpC6 in PIC signaling using a mouse model lacking TrpC6. To address this aim, we evaluated graded pressure (20-90 mmHg), depolarization (4-80 mM KCl)-, and adrenergic receptor (phenylephrine; PE 10-7-10-4 M)-mediated constriction of isolated middle cerebral artery (MCA) segments from 9-wk-old male wild-type (TrpC6+/+, n = 7) and homozygous null (TrpC6-/-, n = 9) TrpC6 mice (Jackson Laboratories). Isolated MCA segments were cannulated and pressurized with physiological salt solution using pressure myography (Living Systems). Vasoconstrictor responses to KCl and PE were identical in TrpC6-/- and TrpC6+/+ mice. In contrast, PIC responses were totally abolished in TrpC6-/- mice. At 90 mmHg, the calculated myogenic tone was -0.8 ± 0.5 vs. 10.7 ± 1.7%, P = 0.0002 in TrpC6-/- and TrpC6+/+ mice, respectively. Additionally, there were no changes in mechanical properties of circumferential wall strain and stress or morphological properties of wall thickness and wall-to-lumen ratio at 50 mmHg between TrpPC6-/- and TrpC6+/+ mice. Although these results demonstrate that TrpC6 is critical for the integrated PIC response, they do not identify whether TrpC6 acts as a mechanosensor or a downstream signaling component.NEW & NOTEWORTHY Pressure-induced, but not agonist-induced, vasoconstriction is abolished in the middle cerebral artery (MCA) of TrpC6 null mice. TrpC6 localization in dissociated cerebral vascular smooth muscle cells is primarily cytoplasmic and not associated with the surface membrane where a mechanoelectrical coupler might be expected. These findings suggest that TrpC6 is required for transduction of pressure-induced constriction in the MCA; however, its role as a mechanoelectrical coupler or downstream signal amplifier remains unresolved.
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Affiliation(s)
- Zoltan Nemeth
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, Mississippi
| | - Emily Hildebrandt
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, Mississippi
| | - Michael J Ryan
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, Mississippi
| | - Joey P Granger
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, Mississippi
| | - Heather A Drummond
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, Mississippi
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Maznychenko AV, Mankivska OP, Sokolowska (Vereshchaka) IV, Kopyak BS, Tomiak T, Bulgakova NV, Gonchar OO, Prylutskyy YI, Ritter U, Mishchenko IV, Kostyukov AI. C60 fullerenes increase the intensity of rotational movements in non-anesthetized hemiparkinsonic rats. Acta Neurobiol Exp (Wars) 2020. [DOI: 10.21307/ane-2020-003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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22
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Limberg JK, Casey DP, Trinity JD, Nicholson WT, Wray DW, Tschakovsky ME, Green DJ, Hellsten Y, Fadel PJ, Joyner MJ, Padilla J. Assessment of resistance vessel function in human skeletal muscle: guidelines for experimental design, Doppler ultrasound, and pharmacology. Am J Physiol Heart Circ Physiol 2019; 318:H301-H325. [PMID: 31886718 DOI: 10.1152/ajpheart.00649.2019] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The introduction of duplex Doppler ultrasound almost half a century ago signified a revolutionary advance in the ability to assess limb blood flow in humans. It is now widely used to assess blood flow under a variety of experimental conditions to study skeletal muscle resistance vessel function. Despite its pervasive adoption, there is substantial variability between studies in relation to experimental protocols, procedures for data analysis, and interpretation of findings. This guideline results from a collegial discussion among physiologists and pharmacologists, with the goal of providing general as well as specific recommendations regarding the conduct of human studies involving Doppler ultrasound-based measures of resistance vessel function in skeletal muscle. Indeed, the focus is on methods used to assess resistance vessel function and not upstream conduit artery function (i.e., macrovasculature), which has been expertly reviewed elsewhere. In particular, we address topics related to experimental design, data collection, and signal processing as well as review common procedures used to assess resistance vessel function, including postocclusive reactive hyperemia, passive limb movement, acute single limb exercise, and pharmacological interventions.
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Affiliation(s)
- Jacqueline K Limberg
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri
| | - Darren P Casey
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa, Iowa City, Iowa.,François M. Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, Iowa.,Fraternal Order of Eagles Diabetes Research, Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Joel D Trinity
- Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah.,Department of Internal Medicine, Division of Geriatrics, University of Utah, Salt Lake City, Utah.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
| | | | - D Walter Wray
- Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah.,Department of Internal Medicine, Division of Geriatrics, University of Utah, Salt Lake City, Utah.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
| | - Michael E Tschakovsky
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
| | - Daniel J Green
- School of Human Sciences (Exercise and Sport Science), University of Western Australia, Perth, Western Australia, Australia
| | - Ylva Hellsten
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Paul J Fadel
- Department of Kinesiology, University of Texas at Arlington, Arlington, Texas
| | | | - Jaume Padilla
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri.,Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
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23
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Azevedo RDA, Béjar Saona JE, Inglis EC, Iannetta D, Murias JM. The effect of the fraction of inspired oxygen on the NIRS-derived deoxygenated hemoglobin "breakpoint" during ramp-incremental test. Am J Physiol Regul Integr Comp Physiol 2019; 318:R399-R409. [PMID: 31850819 DOI: 10.1152/ajpregu.00291.2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
During ramp-incremental (RI) exercise to exhaustion, the near-infrared spectroscopy-derived deoxygenated hemoglobin ([HHb]) signal in the vastus lateralis muscle shows a linear increase up to a point at which a plateau-like response is manifested ([HHb]bp). This study investigated if 1) the [HHb]bp is affected by different fractions of inspired O2 (FIO2) [hypoxia (16%; HYPO); normoxia (21%; NORM); hyperoxia (30%; HYPER)]; and 2) an abrupt change to hyperoxic-inspired gas just before the occurrence of the [HHb]bp (HYPERSWITCH) would affect the [HHb] plateau-like response. Ten physically active male participants reported to the laboratory on four separate occasions to perform an RI test to exhaustion in NORM, HYPO, and HYPER and an RI test to exhaustion with an abrupt increase in FIO2 (30%; HYPERSWITCH) 15 W before the power output (PO) associated with [HHb]bp in normoxia. PO, [HHb], tissue O2 (StO2), and pulse O2 saturation (SpO2) were recorded continuously. Peak PO was significantly lower in HYPO (290 ± 21 W) and higher in HYPER (321 ± 22 W) and HYPERSWITCH (320 ± 19 W) compared with NORM (311 ± 18 W). The PO associated with [HHb]bp was not different between NORM and HYPER (246 ± 23 vs. 247 ± 24 W), but it was lower in HYPO (198 ± 31 W) than NORM and HYPER. The PO associated with the [HHb]bp in HYPERSWITCH (240 ± 23) was not different compared with NORM. HYPER and HYPERSWITCH resulted in greater StO2 and SpO2 compared with NORM. These results suggest that the [HHb]bp response is not dependent of O2 driving pressure and that other physiological mechanisms might determine its occurrence.
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Affiliation(s)
| | | | | | - Danilo Iannetta
- Faculty of Kinesiology, University of Calgary, Calgary, Canada
| | - Juan M Murias
- Faculty of Kinesiology, University of Calgary, Calgary, Canada
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Ušaj A, Mekjavic IB, Kapus J, McDonnell AC, Jaki Mekjavic P, Debevec T. Muscle Oxygenation During Hypoxic Exercise in Children and Adults. Front Physiol 2019; 10:1385. [PMID: 31787903 PMCID: PMC6854007 DOI: 10.3389/fphys.2019.01385] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 10/21/2019] [Indexed: 12/31/2022] Open
Abstract
INTRODUCTION While hypoxia is known to decrease peak oxygen uptake ( V . o 2 max) and maximal power output in both adults and children its influence on submaximal exercise cardiorespiratory and, especially, muscle oxygenation responses remains unclear. METHODS Eight pre-pubertal boys (age = 8 ± 2 years.; body mass (BM) = 29 ± 7 kg) and seven adult males (age = 39 ± 4 years.; BM = 80 ± 8 kg) underwent graded exercise tests in both normoxic (PiO2 = 134 ± 0.4 mmHg) and hypoxic (PiO2 = 105 ± 0.6 mmHg) condition. Continuous breath-by-breath gas exchange and near infrared spectroscopy measurements, to assess the vastus lateralis oxygenation, were performed during both tests. The gas exchange threshold (GET) and muscle oxygenation thresholds were subsequently determined for both groups in both conditions. RESULTS In both groups, hypoxia did not significantly alter either GET or the corresponding V . o 2 at GET. In adults, higher V . E levels were observed in hypoxia (45 ± 6 l/min) compared to normoxia (36 ± 6 l/min, p < 0.05) at intensities above GET. In contrast, in children both the hypoxic V . E and V . o 2 responses were significantly greater than those observed in normoxia only at intensities below GET (p < 0.01 for V . E and p < 0.05 for V . o 2). Higher exercise-related heart rate (HR) levels in hypoxia, compared to normoxia, were only noted in adults (p < 0.01). Interestingly, hypoxia per se did not influence the muscle oxygenation thresholds during exercise in neither group. However, and in contrast to adults, the children exhibited significantly higher total hemoglobin concentration during hypoxic as compared to normoxic exercise (tHb) at lower exercise intensities (30 and 60 W, p = 0.01). CONCLUSION These results suggest that in adults, hypoxia augments exercise ventilation at intensities above GET and might also maintain muscle blood oxygenation via increased HR. On the other hand, children exhibit a greater change of muscle blood perfusion, oxygen uptake as well as ventilation at exercise intensities below GET.
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Affiliation(s)
- Anton Ušaj
- Faculty of Sport, University of Ljubljana, Ljubljana, Slovenia
| | - Igor B Mekjavic
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia.,Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
| | - Jernej Kapus
- Faculty of Sport, University of Ljubljana, Ljubljana, Slovenia
| | - Adam C McDonnell
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
| | | | - Tadej Debevec
- Faculty of Sport, University of Ljubljana, Ljubljana, Slovenia.,Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
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25
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Girard O, Willis SJ, Purnelle M, Scott BR, Millet GP. Separate and combined effects of local and systemic hypoxia in resistance exercise. Eur J Appl Physiol 2019; 119:2313-2325. [PMID: 31468172 DOI: 10.1007/s00421-019-04217-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 08/21/2019] [Indexed: 12/31/2022]
Abstract
PURPOSES This study quantified performance, physiological, and perceptual responses during resistance exercise to task failure with blood flow restriction (BFR), in systemic hypoxia, and with these stimuli combined. METHODS Fourteen young men were tested for 1-repetition maximum (1RM) in the barbell biceps curl and lying triceps extension exercises. On separate visits, subjects performed exercise trials (4 sets to failure at 70% 1RM with 90 s between sets) in six separate randomized conditions, i.e., in normoxia or hypoxia (fraction of inspired oxygen = 20.9% and 12.9%, respectively) combined with three different levels of BFR (0%, 45%, or 60% of resting arterial occlusion pressure). Muscle activation and oxygenation were monitored via surface electromyography and near-infrared spectroscopy, respectively. Arterial oxygen saturation, heart rate, and perceptual responses were assessed following each set. RESULTS Compared to set 1, the number of repetitions before failure decreased in sets 2, 3, and 4 for both exercises (all P < 0.001), independently of the condition (P > 0.065). Arterial oxygen saturation was lower with systemic hypoxia (P < 0.001), but not BFR, while heart rate did not differ between conditions (P > 0.341). Muscle oxygenation and activation during exercise trials remained unaffected by the different conditions (all P ≥ 0.206). A significant main effect of time, but not condition, was observed for overall perceived discomfort, difficulty breathing, and limb discomfort (all P < 0.001). CONCLUSION Local and systemic hypoxic stimuli, or a combination of both, did not modify the fatigue-induced change in performance, trends of muscle activation or oxygenation, nor exercise-related sensations during a multi-set resistance exercise to task failure.
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Affiliation(s)
- Olivier Girard
- Murdoch Applied Sports Science (MASS) Laboratory, Murdoch University, Perth, Australia. .,Faculty of Biology and Medicine, Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland.
| | - Sarah J Willis
- Faculty of Biology and Medicine, Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Marin Purnelle
- Faculty of Biology and Medicine, Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Brendan R Scott
- Murdoch Applied Sports Science (MASS) Laboratory, Murdoch University, Perth, Australia
| | - Grégoire P Millet
- Faculty of Biology and Medicine, Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
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26
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Eiken FL, Pedersen BL, Bækgaard N, Eiberg JP. Diagnostic methods for measurement of peripheral blood flow during exercise in patients with type 2 diabetes and peripheral artery disease: a systematic review. INT ANGIOL 2019; 38:62-69. [PMID: 30860342 DOI: 10.23736/s0392-9590.18.04051-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
INTRODUCTION Measurement of systolic ankle and to some extent toe pressure in patients suffering from combined type 2 diabetes mellitus (T2DM) and peripheral arterial disease (PAD) face several obstacles due to complex changes in the vascular bed. The aim of this review was to address the current literature on blood flow during exercise in patients with PAD and T2DM and assess the feasibility of these methods to diagnose and grade arterial insufficiency. EVIDENCE ACQUISITION A systematic review of the PubMed and EMBASE databases, supplemented by hand searching was performed according to PRISMA guidelines. Clinical studies evaluating methods to investigate peripheral blood flow in patients with PAD and T2DM during exercise were included. EVIDENCE SYNTHESIS In total nine eligible studies consisting of 1105 non-diabetic PAD patients, 336 diabetic PAD patients, 161 diabetic patients without PAD and 69 healthy controls were included in the review. Near-infrared spectroscopy (NIRS) was described in three studies, transcutaneous oxygen pressure measurement (TcpO2) in two and the following methods described in single studies: thermodilution, contrast enhanced ultrasound (CEUS), scintigraphy and TcpO2 in combination with ultrasound. These studies shows that patients with PAD and T2DM compared with patients with only PAD suffers different atherosclerotic lesions characterised by increased arterial stiffness and microcirculation abnormalities, not well differentiated by pressure measurement alone. Investigating patients with PAD and T2DM during exercise reveals that NIRS, TcpO2, CEUS, and scintigraphy have distinct advantages over ankle and toe-pressure. CONCLUSIONS Using methods like NIRS, TcpO2, CEUS and scintigraphy, peripheral blood flow during exercise can be measured at a detailed level and potentially improve future severity grading in patients with combined T2DM and PAD.
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Affiliation(s)
- Frederik L Eiken
- Department of Vascular Surgery, Rigshospitalet 3111, Copenhagen, Denmark
| | - Brian L Pedersen
- Department of Vascular Surgery, Rigshospitalet 3111, Copenhagen, Denmark -
| | - Niels Bækgaard
- Department of Vascular Surgery, Rigshospitalet 3111, Copenhagen, Denmark
| | - Jonas P Eiberg
- Department of Vascular Surgery, Rigshospitalet 3111, Copenhagen, Denmark.,Copenhagen Academy of Medical Education and Simulation (CAMES), Rigshospitalet, Copenhagen, Denmark.,University of Copenhagen, Copenhagen, Denmark
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27
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Impairment on Cardiopulmonary Function after Marathon: Role of Exhaled Nitric Oxide. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:5134360. [PMID: 30911346 PMCID: PMC6398013 DOI: 10.1155/2019/5134360] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 01/08/2019] [Indexed: 12/18/2022]
Abstract
Background The endurance exercise is capable of inducing skeletal muscle, heart, and respiratory fatigue, evidenced by morphofunctional cardiac changes, release of myocardial injury biomarkers, and reduction of maximal voluntary ventilation and oxygen consumption (VO2) at peak exercise. Purpose The aim of this study was to investigate whether marathoners present cardiac fatigue after marathon and whether it correlates with pulmonary levels of exhaled nitric oxide (eNO) and pulmonary inflammation. Methods 31 male marathoners, age 39 ± 9 years, were evaluated by cardiopulmonary exercise test three weeks before and between three and 15 days after a marathon; eNO analysis and spirometry were evaluated before, immediately after, and 24 and 72 hours after the marathon, and sputum cellularity and cytokine level were assessed before and after the marathon. Results Marathon induced an increase in the percentage of macrophages, neutrophils (from 0.65% to 4.28% and 6.79% to 14.11%, respectively), and epithelial cells and a decrease in cytokines in induced sputum, followed by an increase in eNO concentration (20 ± 11 to 35 ± 19 ppb), which presented a significant reduction 24 and 72 hours after marathon (9 ± 12 e 12 ± 9 ppb, p < 0.05). We observed a decrease in the spirometry parameters in all time points assessed after the marathon (p < 0.05) as well as in cardiopulmonary capacity, evidenced by a reduction in VO2 and ventilation peaks (57 ± 6 to 55 ± 6 mL·min-1·Kg-1 and 134 ± 19 to 132 ± 18 Lpm, respectively, p < 0.05). Finally, we observed a negative correlation between the decrease in forced expiratory volume and decrease in eNO 24 and 72 hours after marathon (r = -0.4, p = 0.05). Conclusion Reduction in eNO bioavailability after marathon prevents the reduction in cardiopulmonary capacity induced by acute inflammatory pattern after marathon.
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28
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Effects of exercise in normobaric hypoxia on hemodynamics during muscle metaboreflex activation in normoxia. Eur J Appl Physiol 2019; 119:1137-1148. [DOI: 10.1007/s00421-019-04103-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Accepted: 02/13/2019] [Indexed: 01/21/2023]
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Hearon CM, Richards JC, Racine ML, Luckasen GJ, Larson DG, Dinenno FA. Amplification of endothelium-dependent vasodilatation in contracting human skeletal muscle: role of K IR channels. J Physiol 2018; 597:1321-1335. [PMID: 30506579 DOI: 10.1113/jp276998] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 11/29/2018] [Indexed: 12/14/2022] Open
Abstract
KEY POINTS In humans, the vasodilatory response to skeletal muscle contraction is mediated in part by activation of inwardly rectifying potassium (KIR ) channels. Evidence from animal models suggest that KIR channels serve as electrical amplifiers of endothelium-dependent hyperpolarization (EDH). We found that skeletal muscle contraction amplifies vasodilatation to the endothelium-dependent agonist ACh, whereas there was no change in the vasodilatory response to sodium nitroprusside, an endothelium-independent nitric oxide donor. Blockade of KIR channels reduced the exercise-induced amplification of ACh-mediated vasodilatation. Conversely, pharmacological activation of KIR channels in quiescent muscle via intra-arterial infusion of KCl independently amplified the vasodilatory response to ACh. This study is the first in humans to demonstrate that specific endothelium-dependent vasodilatory signalling is amplified in the vasculature of contracting skeletal muscle and that KIR channels may serve as amplifiers of EDH-like vasodilatory signalling in humans. ABSTRACT The local vasodilatory response to muscle contraction is due in part to the activation of inwardly rectifying potassium (KIR ) channels. Evidence from animal models suggest that KIR channels function as 'amplifiers' of endothelium-dependent vasodilators. We tested the hypothesis that contracting muscle selectively amplifies endothelium-dependent vasodilatation via activation of KIR channels. We measured forearm blood flow (Doppler ultrasound) and calculated changes in vascular conductance (FVC) to local intra-arterial infusion of ACh (endothelium-dependent dilator) during resting conditions, handgrip exercise (5% maximum voluntary contraction) or sodium nitroprusside (SNP; endothelium-independent dilator) which served as a high-flow control condition (n = 7, young healthy men and women). Trials were performed before and after blockade of KIR channels via infusion of barium chloride. Exercise augmented peak ACh-mediated vasodilatation (ΔFVC saline: 117 ± 14; exercise: 236 ± 21 ml min-1 (100 mmHg)-1 ; P < 0.05), whereas SNP did not impact ACh-mediated vasodilatation. Blockade of KIR channels attenuated the exercise-induced augmentation of ACh. In eight additional subjects, SNP was administered as the experimental dilator. In contrast to ACh, exercise did not alter SNP-mediated vasodilatation (ΔFVC saline: 158 ± 35; exercise: 121 ± 22 ml min-1 (100 mmHg)-1 ; n.s.). Finally, in a subset of six subjects, direct pharmacological activation of KIR channels in quiescent muscle via infusion of KCl amplified peak ACh-mediated vasodilatation (ΔFVC saline: 97 ± 15, KCl: 142 ± 16 ml min-1 (100 mmHg)-1 ; respectively; P < 0.05). These findings indicate that skeletal muscle contractions selectively amplify endothelium-dependent vasodilatory signalling via activation of KIR channels, and this may be an important mechanism contributing to the normal vasodilatory response to exercise in humans.
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Affiliation(s)
- Christopher M Hearon
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, 80523, USA
| | - Jennifer C Richards
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, 80523, USA
| | - Mathew L Racine
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, 80523, USA
| | - Gary J Luckasen
- Medical Center of the Rockies Foundation, University of Colorado Health, Loveland, CO, USA
| | - Dennis G Larson
- Medical Center of the Rockies Foundation, University of Colorado Health, Loveland, CO, USA
| | - Frank A Dinenno
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, 80523, USA.,Center for Cardiovascular Research, Colorado State University, Fort Collins, CO, 80523, USA
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30
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Fryer S, Stone K, Dickson T, Wilhelmsen A, Cowen D, Faulkner J, Lambrick D, Stoner L. The effects of 4 weeks normobaric hypoxia training on microvascular responses in the forearm flexor. J Sports Sci 2018; 37:1235-1241. [PMID: 30558476 DOI: 10.1080/02640414.2018.1554177] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Intermittent exposure to hypoxia can lead to improved endurance performance. Currently, it is unclear whether peripheral adaptions play a role in improving oxygen delivery and utilization following both training and detraining. This study aimed to characterize skeletal muscle blood flow (mBF), oxygen consumption (mV̇O2), and perfusion adaptations to i) 4-weeks handgrip training in hypoxic and normoxic conditions, and ii) following 4-weeks detraining. Using a randomised crossover design, 9 males completed 30-min handgrip training four times a week in hypoxic (14% FiO2 ~ 3250m altitude) and normoxic conditions. mBF, mV̇O2 and perfusion were assessed pre, post 4-weeks training, and following 4-weeks detraining. Hierarchical linear modelling found that mV̇O2 increased at a significantly faster rate (58%) with hypoxic training (0.09 mlO2·min-1 · 100g-1 per week); perfusion increased at a significantly (69%) faster rate with hypoxic training (3.72 μM per week). mBF did not significantly change for the normoxic condition, but there was a significant increase of 0.38 ml· min-1 · 100ml-1 per week (95% CI: 0.35, 0.40) for the hypoxic condition. During 4-weeks detraining, mV̇O2 and perfusion significantly declined at similar rates for both conditions, whereas mBF decreased significantly faster following hypoxic training. Four weeks hypoxic training increases the delivery and utilisation of oxygen in the periphery.
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Affiliation(s)
- S Fryer
- a School of Sport and Exercise , University of Gloucestershire , Gloucester , UK
| | - K Stone
- a School of Sport and Exercise , University of Gloucestershire , Gloucester , UK
| | - T Dickson
- a School of Sport and Exercise , University of Gloucestershire , Gloucester , UK
| | - A Wilhelmsen
- b School of Life Sciences, Metabolic and Molecular Physiology Research Group , University of Nottingham , UK
| | - D Cowen
- a School of Sport and Exercise , University of Gloucestershire , Gloucester , UK
| | - J Faulkner
- c Faculty of Business, Law and Sport , University of Winchester , Winchester , UK
| | - D Lambrick
- d Faculty of Health Sciences , University of Southampton , Southampton , UK
| | - L Stoner
- e Department of Sport and Exercise , University of North Carolina , Chapel Hill , NC , USA
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Mansur AP, Alvarenga GS, Kopel L, Gutierrez MA, Consolim-Colombo FM, Abrahão LH, Lage SG. Cerebral blood flow changes during intermittent acute hypoxia in patients with heart failure. J Int Med Res 2018; 46:4214-4225. [PMID: 30130981 PMCID: PMC6166355 DOI: 10.1177/0300060518791691] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Objective Heart failure (HF) is associated with intermittent hypoxia, and the effects of this hypoxia on the cardiovascular system are not well understood. This study was performed to compare the effects of acute hypoxia (10% oxygen) between patients with and without HF. Methods Fourteen patients with chronic HF and 17 matched control subjects were enrolled. Carotid artery changes were examined during the first period of hypoxia, and brachial artery changes were examined during the second period of hypoxia. Data were collected at baseline and after 2 and 4 minutes of hypoxia. Norepinephrine, epinephrine, dopamine, and renin were measured at baseline and after 4 minutes hypoxia. Results The carotid blood flow, carotid systolic diameter, and carotid diastolic diameter increased and the carotid resistance decreased in patients with HF. Hypoxia did not change the carotid compliance, distensibility, brachial artery blood flow and diameter, or concentrations of sympathomimetic amines in patients with HF, but hypoxia increased the norepinephrine level in the control group. Hypoxia increased minute ventilation and decreased the oxygen saturation and end-tidal carbon dioxide concentration in both groups. Conclusion Hypoxia-induced changes in the carotid artery suggest an intensification of compensatory mechanisms for preservation of cerebral blood flow in patients with HF.
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Affiliation(s)
- Antonio P Mansur
- Heart Institute (InCor) - Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Brazil
| | - Glaura Souza Alvarenga
- Heart Institute (InCor) - Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Brazil
| | - Liliane Kopel
- Heart Institute (InCor) - Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Brazil
| | - Marco Antonio Gutierrez
- Heart Institute (InCor) - Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Brazil
| | | | - Ludhmila Hajjar Abrahão
- Heart Institute (InCor) - Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Brazil
| | - Silvia Gelas Lage
- Heart Institute (InCor) - Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Brazil
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Golub AS, Dodhy SC, Pittman RN. Oxygen dependence of respiration in rat spinotrapezius muscle contracting at 0.5-8 twitches per second. J Appl Physiol (1985) 2018; 125:124-133. [PMID: 29494286 DOI: 10.1152/japplphysiol.01136.2016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The oxygen dependence of respiration was obtained in situ in microscopic regions of rat spinotrapezius muscle for different levels of metabolic activity produced by electrical stimulation at rates from 0.5 to 8 Hz. The rate of O2 consumption (V̇o2) was measured with phosphorescence quenching microscopy (PQM) as the rate of O2 disappearance in a muscle with rapid flow arrest. The phosphorescent oxygen probe was loaded into the interstitial space of the muscle to give O2 tension (Po2) in the interstitium. A set of sigmoid curves relating the Po2 dependence of V̇o2 was obtained with a Po2-dependent region below a characteristic Po2 (~30 mmHg) and a Po2-independent region above this Po2. The V̇o2(Po2) plots were fit by the Hill equation containing O2 demand (rest to 8 Hz: 216 ± 26 to 636 ± 77 nl O2/cm3 s) and the Po2 value corresponding to O2 demand/2 (rest to 8 Hz: 22 ± 4 to 11 ± 1 mmHg). The initial Po2 and V̇o2 pairs of values measured at the moment of flow arrest formed a straight line, determining the rate of oxygen supply. This line had a negative slope, equal to the oxygen conductance for the O2 supply chain. For each level of tissue blood flow the set of possible values of Po2 and V̇o2 consists of the intersection points between this O2 supply line and the set of V̇o2 curves. An electrical analogy for the intraorgan O2 supply and consumption is an inverting transistor amplifier, which allows the use of graphic analysis methods for prediction of the behavior of the oxygen processing system in organs. NEW & NOTEWORTHY The sigmoidal shape of curves describing oxygen dependence of muscle respiration varies from basal to maximal workload and characterizes the oxidative metabolism of muscle. The rate of O2 supply depends on extracellular O2 tension and is determined by the overall oxygen conductance in the muscle. The dynamics of oxygen consumption is determined by the supply line that intersects the oxygen demand curves. An electrical analogy for the oxygen supply/consumption system is an inverting transistor amplifier.
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Affiliation(s)
- Aleksander S Golub
- Department of Physiology and Biophysics, Medical College of Virginia Campus, Virginia Commonwealth University , Richmond, Virginia
| | - Sami C Dodhy
- Department of Physiology and Biophysics, Medical College of Virginia Campus, Virginia Commonwealth University , Richmond, Virginia
| | - Roland N Pittman
- Department of Physiology and Biophysics, Medical College of Virginia Campus, Virginia Commonwealth University , Richmond, Virginia
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Acute Limb Ischemia-Much More Than Just a Lack of Oxygen. Int J Mol Sci 2018; 19:ijms19020374. [PMID: 29373539 PMCID: PMC5855596 DOI: 10.3390/ijms19020374] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 01/17/2018] [Accepted: 01/23/2018] [Indexed: 12/12/2022] Open
Abstract
Acute ischemia of an extremity occurs in several stages, a lack of oxygen being the primary contributor of the event. Although underlying patho-mechanisms are similar, it is important to determine whether it is an acute or chronic event. Healthy tissue does not contain enlarged collaterals, which are formed in chronically malperfused tissue and can maintain a minimum supply despite occlusion. The underlying processes for enhanced collateral blood flow are sprouting vessels from pre-existing vessels (via angiogenesis) and a lumen extension of arterioles (via arteriogenesis). While disturbed flow patterns with associated local low shear stress upregulate angiogenesis promoting genes, elevated shear stress may trigger arteriogenesis due to increased blood volume. In case of an acute ischemia, especially during the reperfusion phase, fluid transfer occurs into the tissue while the vascular bed is simultaneously reduced and no longer reacts to vaso-relaxing factors such as nitric oxide. This process results in an exacerbative cycle, in which increased peripheral resistance leads to an additional lack of oxygen. This whole process is accompanied by an inundation of inflammatory cells, which amplify the inflammatory response by cytokine release. However, an extremity is an individual-specific composition of different tissues, so these processes may vary dramatically between patients. The image is more uniform when broken down to the single cell stage. Because each cell is dependent on energy produced from aerobic respiration, an event of acute hypoxia can be a life-threatening situation. Aerobic processes responsible for yielding adenosine triphosphate (ATP), such as the electron transport chain and oxidative phosphorylation in the mitochondria, suffer first, thus disrupting the integrity of cellular respiration. One consequence of this is irreparable damage of the cell membrane due to an imbalance of electrolytes. The eventual increase in net fluid influx associated with a decrease in intracellular pH is considered an end-stage event. Due to the lack of ATP, individual cell organelles can no longer sustain their activity, thus initiating the cascade pathways of apoptosis via the release of cytokines such as the BCL2 associated X protein (BAX). As ischemia may lead to direct necrosis, inflammatory processes are further aggravated. In the case of reperfusion, the flow of nascent oxygen will cause additional damage to the cell, further initiating apoptosis in additional surrounding cells. In particular, free oxygen radicals are formed, causing severe damage to cell membranes and desoxyribonucleic acid (DNA). However, the increased tissue stress caused by this process may be transient, as radical scavengers may attenuate the damage. Taking the above into final consideration, it is clearly elucidated that acute ischemia and subsequent reperfusion is a process that leads to acute tissue damage combined with end-organ loss of function, a condition that is difficult to counteract.
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Messere A, Ceravolo G, Franco W, Maffiodo D, Ferraresi C, Roatta S. Increased tissue oxygenation explains the attenuation of hyperemia upon repetitive pneumatic compression of the lower leg. J Appl Physiol (1985) 2017; 123:1451-1460. [DOI: 10.1152/japplphysiol.00511.2017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 08/09/2017] [Accepted: 08/15/2017] [Indexed: 11/22/2022] Open
Abstract
The rapid hyperemia evoked by muscle compression is short lived and was recently shown to undergo a rapid decrease even in spite of continuing mechanical stimulation. The present study aims at investigating the mechanisms underlying this attenuation, which include local metabolic mechanisms, desensitization of mechanosensitive pathways, and reduced efficacy of the muscle pump. In 10 healthy subjects, short sequences of mechanical compressions ( n = 3–6; 150 mmHg) of the lower leg were delivered at different interstimulus intervals (ranging from 20 to 160 s) through a customized pneumatic device. Hemodynamic monitoring included near-infrared spectroscopy, detecting tissue oxygenation and blood volume in calf muscles, and simultaneous echo-Doppler measurement of arterial (superficial femoral artery) and venous (femoral vein) blood flow. The results indicate that 1) a long-lasting (>100 s) increase in local tissue oxygenation follows compression-induced hyperemia, 2) compression-induced hyperemia exhibits different patterns of attenuation depending on the interstimulus interval, 3) the amplitude of the hyperemia is not correlated with the amount of blood volume displaced by the compression, and 4) the extent of attenuation negatively correlates with tissue oxygenation ( r = −0,78, P < 0.05). Increased tissue oxygenation appears to be the key factor for the attenuation of hyperemia upon repetitive compressive stimulation. Tissue oxygenation monitoring is suggested as a useful integration in medical treatments aimed at improving local circulation by repetitive tissue compression. NEW & NOTEWORTHY This study shows that 1) the hyperemia induced by muscle compression produces a long-lasting increase in tissue oxygenation, 2) the hyperemia produced by subsequent muscle compressions exhibits different patterns of attenuation at different interstimulus intervals, and 3) the extent of attenuation of the compression-induced hyperemia is proportional to the level of oxygenation achieved in the tissue. The results support the concept that tissue oxygenation is a key variable in blood flow regulation.
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Affiliation(s)
| | - Gianluca Ceravolo
- Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Turin, Italy
| | - Walter Franco
- Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Turin, Italy
| | - Daniela Maffiodo
- Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Turin, Italy
| | - Carlo Ferraresi
- Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Turin, Italy
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de Freitas MC, Gerosa-Neto J, Zanchi NE, Lira FS, Rossi FE. Role of metabolic stress for enhancing muscle adaptations: Practical applications. World J Methodol 2017; 7:46-54. [PMID: 28706859 PMCID: PMC5489423 DOI: 10.5662/wjm.v7.i2.46] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 03/17/2017] [Indexed: 02/06/2023] Open
Abstract
Metabolic stress is a physiological process that occurs during exercise in response to low energy that leads to metabolite accumulation [lactate, phosphate inorganic (Pi) and ions of hydrogen (H+)] in muscle cells. Traditional exercise protocol (i.e., Resistance training) has an important impact on the increase of metabolite accumulation, which influences hormonal release, hypoxia, reactive oxygen species (ROS) production and cell swelling. Changes in acute exercise routines, such as intensity, volume and rest between sets, are determinants for the magnitude of metabolic stress, furthermore, different types of training, such as low-intensity resistance training plus blood flow restriction and high intensity interval training, could be used to maximize metabolic stress during exercise. Thus, the objective of this review is to describe practical applications that induce metabolic stress and the potential effects of metabolic stress to increase systemic hormonal release, hypoxia, ROS production, cell swelling and muscle adaptations.
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Bentley RF, Poitras VJ, Hong T, Tschakovsky ME. Characteristics and effectiveness of vasodilatory and pressor compensation for reduced relaxation time during rhythmic forearm contractions. Exp Physiol 2017; 102:621-634. [PMID: 28397384 DOI: 10.1113/ep086069] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 03/30/2017] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? Reduced relaxation time between contractions in exercise requires increased vasodilatation and/or pressor response to prevent hypoperfusion and potential compromise to exercise tolerance. However, it remains unknown whether and to what extent local vasodilatation and/or systemic pressor compensation occurs and whether the efficacy of compensation is exercise intensity dependent. What is the main finding and its importance? We demonstrate that in a forearm exercise model vasodilatory but not pressor compensation occurs and is adequate to prevent hypoperfusion below but not above ∼40% peak work rate. Inadequate compensation occurs with exercise still well inside the submaximal domain, despite a vasodilatory reserve, and compromises exercise performance. During muscle contraction in rhythmic exercise, muscle blood flow is significantly impeded by microvascular compression. The purpose of this study was to establish the nature and magnitude of vasodilatory and/or pressor compensatory responses during forearm exercise in the face of an increased duration of mechanical microvascular compression, and whether the effectiveness of such compensation was exercise intensity dependent. Seven healthy males (21.0 ± 1.8 years old) completed progressive forearm exercise (24.5 N every 3 min; 2 s contraction-4 s relaxation duty cycle) in two conditions: control (CON), 2 s 100 mmHg forearm cuff inflation during contraction; and impedance (IMP), extension of cuff inflation 2 s beyond contraction. Forearm blood flow (in millilitres per minute); brachial artery Doppler and echo ultrasound), mean arterial blood pressure (in millimetres of mercury; finger photoplethysmography) and exercising forearm venous effluent (antecubital vein catheter) measurements revealed an exercise intensity-dependent compensatory vasodilatation effectiveness whereby increased vasodilatation fully protected forearm blood flow up to the 30% exercise intensity in IMP. Above this exercise intensity, forearm blood flow was defended only in part, although submaximal oxygen uptake was not compromised for any completed work rate. As a result, peak exercise intensity (175 ± 22 versus 196 ± 28 N, P = 0.04) and oxygen delivery (76 ± 14 versus 112 ± 22 ml O2 min-1 , P = 0.01) were significantly reduced in IMP compared with CON. In conclusion, reducing relaxation time compromised exercise capacity without compromise to oxygen uptake. Vasodilatory compensation was complete at lower but not higher exercise intensities, whereas pressor compensation was absent. The reasons for the exercise intensity dependence of the efficacy of vasodilatory compensation remain to be determined.
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Affiliation(s)
- Robert F Bentley
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada, K7L 3N6
| | - Veronica J Poitras
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada, K7L 3N6
| | - Terrence Hong
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada, K7L 3N6
| | - Michael E Tschakovsky
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada, K7L 3N6
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Prylutskyy YI, Vereshchaka IV, Maznychenko AV, Bulgakova NV, Gonchar OO, Kyzyma OA, Ritter U, Scharff P, Tomiak T, Nozdrenko DM, Mishchenko IV, Kostyukov AI. C 60 fullerene as promising therapeutic agent for correcting and preventing skeletal muscle fatigue. J Nanobiotechnology 2017; 15:8. [PMID: 28086894 PMCID: PMC5237293 DOI: 10.1186/s12951-016-0246-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 12/30/2016] [Indexed: 12/26/2022] Open
Abstract
Background Bioactive soluble carbon nanostructures, such as the C60 fullerene can bond with up to six electrons, thus serving by a powerful scavenger of reactive oxygen species similarly to many natural antioxidants, widely used to decrease the muscle fatigue effects. The aim of the study is to define action of the pristine C60 fullerene aqueous colloid solution (C60FAS), on the post-fatigue recovering of m. triceps surae in anaesthetized rats. Results During fatigue development, we observed decrease in the muscle effort level before C60FAS administration. After the application of C60FAS, a slower effort decrease, followed by the prolonged retention of a certain level, was recorded. An analysis of the metabolic process changes accompanying muscle fatigue showed an increase in the oxidative stress markers H2O2 (hydrogen peroxide) and TBARS (thiobarbituric acid reactive substances) in relation to the intact muscles. After C60FAS administration, the TBARS content and H2O2 level were decreased. The endogenous antioxidant system demonstrated a similar effect because the GSH (reduced glutathione) in the muscles and the CAT (catalase) enzyme activity were increased during fatigue. Conclusions C60FAS leads to reduction in the recovery time of the muscle contraction force and to increase in the time of active muscle functioning before appearance of steady fatigue effects. Therefore, it is possible that C60FAS affects the prooxidant-antioxidant muscle tissue homeostasis, subsequently increasing muscle endurance.
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Affiliation(s)
- Yurij I Prylutskyy
- Department of Biophysics, Taras Shevchenko National University of Kyiv, Volodymyrska Str. 60, Kiev, 01601, Ukraine
| | - Inna V Vereshchaka
- Department of Movement Physiology, Bogomoletz Institute of Physiology, Bogomoletz Str. 4, Kiev, 01024, Ukraine
| | - Andriy V Maznychenko
- Department of Movement Physiology, Bogomoletz Institute of Physiology, Bogomoletz Str. 4, Kiev, 01024, Ukraine.
| | - Nataliya V Bulgakova
- Department of Movement Physiology, Bogomoletz Institute of Physiology, Bogomoletz Str. 4, Kiev, 01024, Ukraine
| | - Olga O Gonchar
- Department of Hypoxic States Investigation, Bogomoletz Institute of Physiology, Bogomoletz Str. 4, Kiev, 01024, Ukraine
| | - Olena A Kyzyma
- Department of Biophysics, Taras Shevchenko National University of Kyiv, Volodymyrska Str. 60, Kiev, 01601, Ukraine.,Joint Institute for Nuclear Research, Joliot-Curie Str. 6, Dubna, Moscow Region, Russia
| | - Uwe Ritter
- Institute of Chemistry and Biotechnology, Technical University of Ilmenau, Weimarer Str. 25, 98693, Ilmenau, Germany
| | - Peter Scharff
- Institute of Chemistry and Biotechnology, Technical University of Ilmenau, Weimarer Str. 25, 98693, Ilmenau, Germany
| | - Tomasz Tomiak
- University of Physical Education and Sport, Kazimierza Górskiego Str.1, 80-336, Gdansk, Poland
| | - Dmytro M Nozdrenko
- Department of Biophysics, Taras Shevchenko National University of Kyiv, Volodymyrska Str. 60, Kiev, 01601, Ukraine
| | - Iryna V Mishchenko
- Lesia Ukrainka Eastern European National University, Volya Avenue 13, Lutsk, 43025, Ukraine
| | - Alexander I Kostyukov
- Department of Movement Physiology, Bogomoletz Institute of Physiology, Bogomoletz Str. 4, Kiev, 01024, Ukraine
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Louvaris Z, Habazettl H, Asimakos A, Wagner H, Zakynthinos S, Wagner PD, Vogiatzis I. Heterogeneity of blood flow and metabolism during exercise in patients with chronic obstructive pulmonary disease. Respir Physiol Neurobiol 2017; 237:42-50. [PMID: 28057577 DOI: 10.1016/j.resp.2016.12.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 12/19/2016] [Accepted: 12/28/2016] [Indexed: 11/17/2022]
Abstract
The study investigated whether the capacity to regulate muscle blood flow (Q) relative to metabolic demand (VO2) is impaired in COPD. Using six NIRS optodes over the upper, middle and lower vastus lateralis in 6 patients, (FEV1:46±12%predicted) we recorded from each: a) Q by indocyanine green dye injection, b) VO2/Q ratios based on fractional tissue O2 saturation and c) VO2 as their product, during constant-load exercise (at 20%, 50% and 80% of peak capacity) in normoxia and hyperoxia (FIO2:1.0). At 50 and 80%, relative dispersion (RD) for Q, but not for VO2, was greater in normoxia (0.67±0.07 and 0.79±0.08, respectively) compared to hyperoxia (0.57±0.12 and 0.72±0.07, respectively). In both conditions, RD for VO2 and Q significantly increased throughout exercise; however, RD of VO2/Q ratio was minimal (normoxia: 0.12-0.08 vs hyperoxia: 0.13-0.09). Muscle Q and VO2 appear closely matched in COPD patients, indicating a minimal impact of heterogeneity on muscle oxygen availability at submaximal levels of exercise.
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Affiliation(s)
- Zafeiris Louvaris
- Faculty of Physical Education and Sport Sciences, National and Kapodistrian University of Athens, Greece; 1st Department of Critical Care Medicine and Pulmonary Services, Evangelismos Hospital, "M. Simou, and G.P. Livanos Laboratories", National and Kapodistrian University of Athens, Greece; Faculty of Kinesiology and Rehabilitation Sciences, Division of Respiratory Rehabilitation, Department of Rehabilitation Sciences KU Leuven, University Hospital Leuven, Leuven, Belgium.
| | - Helmut Habazettl
- Institute of Physiology, Charité Campus Benjamin Franklin, Berlin, Germany; Institute of Anesthesiology, Deutsches Herzzentrum Berlin, Germany
| | - Andreas Asimakos
- 1st Department of Critical Care Medicine and Pulmonary Services, Evangelismos Hospital, "M. Simou, and G.P. Livanos Laboratories", National and Kapodistrian University of Athens, Greece
| | - Harrieth Wagner
- Department of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Spyros Zakynthinos
- 1st Department of Critical Care Medicine and Pulmonary Services, Evangelismos Hospital, "M. Simou, and G.P. Livanos Laboratories", National and Kapodistrian University of Athens, Greece
| | - Peter D Wagner
- Department of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Ioannis Vogiatzis
- Faculty of Physical Education and Sport Sciences, National and Kapodistrian University of Athens, Greece; 1st Department of Critical Care Medicine and Pulmonary Services, Evangelismos Hospital, "M. Simou, and G.P. Livanos Laboratories", National and Kapodistrian University of Athens, Greece; Department of Sport, Exercise and Rehabilitation, Faculty of Health and Life Sciences, Northumbria University Newcastle, UK
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39
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Jackson WF. Arteriolar oxygen reactivity: where is the sensor and what is the mechanism of action? J Physiol 2016; 594:5055-77. [PMID: 27324312 PMCID: PMC5023707 DOI: 10.1113/jp270192] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 06/13/2016] [Indexed: 01/02/2023] Open
Abstract
Arterioles in the peripheral microcirculation are exquisitely sensitive to changes in PO2 in their environment: increases in PO2 cause vasoconstriction while decreases in PO2 result in vasodilatation. However, the cell type that senses O2 (the O2 sensor) and the signalling pathway that couples changes in PO2 to changes in arteriolar tone (the mechanism of action) remain unclear. Many (but not all) ex vivo studies of isolated cannulated resistance arteries and large, first-order arterioles support the hypothesis that these vessels are intrinsically sensitive to PO2 with the smooth muscle, endothelial cells, or red blood cells serving as the O2 sensor. However, in situ studies testing these hypotheses in downstream arterioles have failed to find evidence of intrinsic O2 sensitivity, and instead have supported the idea that extravascular cells sense O2 . Similarly, ex vivo studies of isolated, cannulated resistance arteries and large first-order arterioles support the hypotheses that O2 -dependent inhibition of production of vasodilator cyclooxygenase products or O2 -dependent destruction of nitric oxide mediates O2 reactivity of these upstream vessels. In contrast, most in vivo studies of downstream arterioles have disproved these hypotheses and instead have provided evidence supporting the idea that O2 -dependent production of vasoconstrictors mediates arteriolar O2 reactivity, with significant regional heterogeneity in the specific vasoconstrictor involved. Oxygen-induced vasoconstriction may serve as a protective mechanism to reduce the oxidative burden to which a tissue is exposed, a process that is superimposed on top of the local mechanisms which regulate tissue blood flow to meet a tissue's metabolic demand.
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Affiliation(s)
- William F Jackson
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, 48824, USA.
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40
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Millet GP, Debevec T, Brocherie F, Malatesta D, Girard O. Therapeutic Use of Exercising in Hypoxia: Promises and Limitations. Front Physiol 2016; 7:224. [PMID: 27375500 PMCID: PMC4902009 DOI: 10.3389/fphys.2016.00224] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 05/30/2016] [Indexed: 01/03/2023] Open
Affiliation(s)
- Gregoire P. Millet
- Institute of Sport Sciences of the University of Lausanne (ISSUL)Lausanne, Switzerland
| | - Tadej Debevec
- Department of Automation, Biocybernetics and Robotics, Jožef Stefan InstituteLjubljana, Slovenia
| | - Franck Brocherie
- Institute of Sport Sciences of the University of Lausanne (ISSUL)Lausanne, Switzerland
| | - Davide Malatesta
- Institute of Sport Sciences of the University of Lausanne (ISSUL)Lausanne, Switzerland
| | - Olivier Girard
- Institute of Sport Sciences of the University of Lausanne (ISSUL)Lausanne, Switzerland
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Lefferts WK, Hughes WE, White CN, Brutsaert TD, Heffernan KS. Effect of acute nitrate supplementation on neurovascular coupling and cognitive performance in hypoxia. Appl Physiol Nutr Metab 2016; 41:133-41. [DOI: 10.1139/apnm-2015-0400] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The matching of oxygen supply to neural demand (i.e., neurovascular coupling (NVC)) is an important determinant of cognitive performance. The impact of hypoxia on NVC remains poorly characterized. NVC is partially modulated by nitric oxide (NO), which may initially decrease in hypoxia. This study investigated the effect of acute NO-donor (nitrate) supplementation on NVC and cognitive function in hypoxia. Twenty healthy men participated in this randomized, double-blind, crossover design study. Following normoxic cognitive/NVC testing, participants consumed either nitrate (NIT) or a NIT-depleted placebo (PLA). Participants then underwent 120 min of hypoxia (11.6% ± 0.1% O2) and all cognitive/NVC testing was repeated. NVC was assessed as change in middle cerebral artery (MCA) blood flow during a cognitive task (incongruent Stroop) using transcranial Doppler. Additional computerized cognitive testing was conducted separately to assess memory, executive function, attention, sensorimotor, and social cognition domains. Salivary nitrite significantly increased following supplementation in hypoxia for NIT (+2.6 ± 1.0 arbitrary units (AU)) compared with PLA (+0.2 ± 0.3 AU; p < 0.05). Memory performance (−6 ± 13 correct) significantly decreased (p < 0.05) in hypoxia while all other cognitive domains were unchanged in hypoxia for both PLA and NIT conditions (p > 0.05). MCA flow increased during Stroop similarly in normoxia (PLA +5 ± 6 cm·s−1, NIT +7 ± 7 cm·s−1) and hypoxia (PLA +5 ± 9 cm·s−1, NIT +6 ± 7 cm·s−1) (p < 0.05) and this increase was not altered by PLA or NIT (p > 0.05). In conclusion, acute hypoxia resulted in significant reductions in memory concomitant with preservation of executive function, attention, and sensorimotor function. Hypoxia had no effect on NVC. Acute NIT supplementation had no effect on NVC or cognitive performance in hypoxia.
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Affiliation(s)
- Wesley K. Lefferts
- The Human Performance Laboratory, Department of Exercise Science, Syracuse University, Syracuse, NY 13244, USA
| | - William E. Hughes
- The Human Performance Laboratory, Department of Exercise Science, Syracuse University, Syracuse, NY 13244, USA
| | - Corey N. White
- Department of Psychology, Syracuse University, Syracuse, NY 13244, USA
| | - Tom D. Brutsaert
- The Human Performance Laboratory, Department of Exercise Science, Syracuse University, Syracuse, NY 13244, USA
| | - Kevin S. Heffernan
- The Human Performance Laboratory, Department of Exercise Science, Syracuse University, Syracuse, NY 13244, USA
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42
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Dinenno FA. Skeletal muscle vasodilation during systemic hypoxia in humans. J Appl Physiol (1985) 2015; 120:216-25. [PMID: 26023228 DOI: 10.1152/japplphysiol.00256.2015] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 05/21/2015] [Indexed: 11/22/2022] Open
Abstract
In humans, the net effect of acute systemic hypoxia in quiescent skeletal muscle is vasodilation despite significant reflex increases in muscle sympathetic vasoconstrictor nerve activity. This vasodilation increases tissue perfusion and oxygen delivery to maintain tissue oxygen consumption. Although several mechanisms may be involved, we recently tested the roles of two endothelial-derived substances during conditions of sympathoadrenal blockade to isolate local vascular control mechanisms: nitric oxide (NO) and prostaglandins (PGs). Our findings indicate that 1) NO normally plays a role in regulating vascular tone during hypoxia independent of the PG pathway; 2) PGs do not normally contribute to vascular tone during hypoxia, however, they do affect vascular tone when NO is inhibited; 3) NO and PGs are not independently obligatory to observe hypoxic vasodilation when assessed as a response from rest to steady-state hypoxia; and 4) combined NO and PG inhibition abolishes hypoxic vasodilation in human skeletal muscle. When the stimulus is exacerbated via combined submaximal rhythmic exercise and systemic hypoxia to cause further red blood cell (RBC) deoxygenation, skeletal muscle blood flow is augmented compared with normoxic exercise via local dilator mechanisms to maintain oxygen delivery to active tissue. Data obtained in a follow-up study indicate that combined NO and PG inhibition during hypoxic exercise blunts augmented vasodilation and hyperemia compared with control (normoxic) conditions by ∼50%; however, in contrast to hypoxia alone, the response is not abolished, suggesting that other local substances are involved. Factors associated with greater RBC deoxygenation such as ATP release, or nitrite reduction to NO, or both likely play a role in regulating this response.
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Affiliation(s)
- Frank A Dinenno
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Center for Cardiovascular Research, Colorado State University, Fort Collins, Colorado
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43
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A review of the pathophysiology and potential biomarkers for peripheral artery disease. Int J Mol Sci 2015; 16:11294-322. [PMID: 25993296 PMCID: PMC4463701 DOI: 10.3390/ijms160511294] [Citation(s) in RCA: 112] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 03/29/2015] [Accepted: 04/08/2015] [Indexed: 12/12/2022] Open
Abstract
Peripheral artery disease (PAD) is due to the blockage of the arteries supplying blood to the lower limbs usually secondary to atherosclerosis. The most severe clinical manifestation of PAD is critical limb ischemia (CLI), which is associated with a risk of limb loss and mortality due to cardiovascular events. Currently CLI is mainly treated by surgical or endovascular revascularization, with few other treatments in routine clinical practice. There are a number of problems with current PAD management strategies, such as the difficulty in selecting the appropriate treatments for individual patients. Many patients undergo repeated attempts at revascularization surgery, but ultimately require an amputation. There is great interest in developing new methods to identify patients who are unlikely to benefit from revascularization and to improve management of patients unsuitable for surgery. Circulating biomarkers that predict the progression of PAD and the response to therapies could assist in the management of patients. This review provides an overview of the pathophysiology of PAD and examines the association between circulating biomarkers and PAD presence, severity and prognosis. While some currently identified circulating markers show promise, further larger studies focused on the clinical value of the biomarkers over existing risk predictors are needed.
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Pedersen BL, Bækgaard N, Quistorff B. A near infrared spectroscopy-based test of calf muscle function in patients with peripheral arterial disease. Int J Angiol 2015; 24:25-34. [PMID: 25780325 DOI: 10.1055/s-0035-1544223] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Background The study aims to test a new, simple, and reliable apparatus and procedure for the diagnostics and treatment evaluation of peripheral arterial disease (PAD). The test apparatus involves near infrared spectroscopy (NIRS) of a main part of the lower leg muscles during isometric flexion and extension of the ankle joint performed with the foot strapped in a specially designed pedal ergometer. Design To evaluate the reproducibility of the new test compared with an existing testing method of treadmill walking. Methods Eleven patients participated in the study: nine patients with claudication and two age-matched patients without claudication. Each patient was tested with an isometric ergometer pedal test and a treadmill test applying NIRS measurements of the anterior tibial and the gastrocnemius muscles (GAS). Tests were repeated three times with randomly selected intervals between individual test runs. Intraclass correlation constant (ICC) was used to describe reproducibility. The ICC was calculated using the area under the NIRS oxygenated hemoglobin (Hbox) curve, the initial velocity of the Hbox recovery curve, force measurements, and walking time. Results The ICC of the GAS was between 0.92-0.95 (foot-pedal) and 0.70-0.98 (tread mill) and of the anterior tibial muscle was between 0.87-0.96 (foot-pedal) and 0.67-0.79 (tread mill). Conclusion In this study, we contribute a new apparatus and test protocol for peripheral arterial disease (PAD) applying NIRS technique and controlled physical activity to evaluate the degree of muscle oxygenation under specific functionally relevant conditions. Thus, we have developed a clinically applicable "easy-to-do" exercise test of patients with chronic PAD which show high reproducibility.
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Affiliation(s)
| | - Niels Bækgaard
- Department of Vascular Surgery, Rigshospitalet and Gentofte Hospital, Copenhagen, Denmark
| | - Bjørn Quistorff
- Department of Biomedical Sciences, University of Copenhagen, The Panum Institute, Copenhagen, Denmark
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Vogiatzis I, Habazettl H, Louvaris Z, Andrianopoulos V, Wagner H, Zakynthinos S, Wagner PD. A method for assessing heterogeneity of blood flow and metabolism in exercising normal human muscle by near-infrared spectroscopy. J Appl Physiol (1985) 2015; 118:783-93. [PMID: 25593285 DOI: 10.1152/japplphysiol.00458.2014] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Heterogeneity in the distribution of both blood flow (Q̇) and O2 consumption (V̇O2) has not been assessed by near-infrared spectroscopy in exercising normal human muscle. We used near-infrared spectroscopy to measure the regional distribution of Q̇ and V̇O2 in six trained cyclists at rest and during constant-load exercise (unloaded pedaling, 20%, 50%, and 80% of peak Watts) in both normoxia and hypoxia (inspired O2 fraction = 0.12). Over six optodes over the upper, middle, and lower vastus lateralis, we recorded 1) indocyanine green dye inflow after intravenous injection to measure Q̇; and 2) fractional tissue O2 saturation (StiO2) to estimate local V̇O2-to-Q̇ ratios (V̇o2/Q̇). Varying both exercise intensity and inspired O2 fraction provided a (directly measured) femoral venous O2 saturation range from about 10 to 70%, and a correspondingly wide range in StiO2. Mean Q̇-weighted StiO2 over the six optodes related linearly to femoral venous O2 saturation in each subject. We used this relationship to compute local muscle venous blood O2 saturation from StiO2 recorded at each optode, from which local V̇O2/Q̇ could be calculated by the Fick principle. Multiplying regional V̇O2/Q̇ by Q̇ yielded the corresponding local V̇O2. While six optodes along only in one muscle may not fully capture the extent of heterogeneity, relative dispersion of both Q̇ and V̇O2 was ∼0.4 under all conditions, while that for V̇O2/Q̇ was minimal (only ∼0.1), indicating in fit young subjects 1) a strong capacity to regulate Q̇ according to regional metabolic need; and 2) a likely minimal impact of heterogeneity on muscle O2 availability.
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Affiliation(s)
- Ioannis Vogiatzis
- Faculty of Physical Education and Sport Sciences, National and Kapodistrian University of Athens, Athens, Greece; Department of Critical Care Medicine and Pulmonary Services, Evangelismos Hospital, "M. Simou and G.P. Livanos Laboratories", National and Kapodistrian University of Athens, Athens, Greece;
| | - Helmut Habazettl
- Institute of Physiology, Charité Campus Benjamin Franklin, Berlin, Germany; Institute of Anesthesiology, German Heart Institute, Berlin, Germany
| | - Zafeiris Louvaris
- Faculty of Physical Education and Sport Sciences, National and Kapodistrian University of Athens, Athens, Greece; Department of Critical Care Medicine and Pulmonary Services, Evangelismos Hospital, "M. Simou and G.P. Livanos Laboratories", National and Kapodistrian University of Athens, Athens, Greece
| | - Vasileios Andrianopoulos
- Department of Critical Care Medicine and Pulmonary Services, Evangelismos Hospital, "M. Simou and G.P. Livanos Laboratories", National and Kapodistrian University of Athens, Athens, Greece
| | - Harrieth Wagner
- Department of Medicine, University of California San Diego, La Jolla, California
| | - Spyros Zakynthinos
- Department of Critical Care Medicine and Pulmonary Services, Evangelismos Hospital, "M. Simou and G.P. Livanos Laboratories", National and Kapodistrian University of Athens, Athens, Greece
| | - Peter D Wagner
- Department of Medicine, University of California San Diego, La Jolla, California; Institute of Clinical Exercise & Health Sciences, University of the West of Scotland, Hamilton, United Kingdom
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Casey DP, Treichler DP, Ganger CT, Schneider AC, Ueda K. Acute dietary nitrate supplementation enhances compensatory vasodilation during hypoxic exercise in older adults. J Appl Physiol (1985) 2014; 118:178-86. [PMID: 25414241 DOI: 10.1152/japplphysiol.00662.2014] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
We have previously demonstrated that aging reduces the compensatory vasodilator response during hypoxic exercise due to blunted nitric oxide (NO) signaling. Recent evidence suggests that NO bioavailability can be augmented by dietary nitrate through the nitrate-nitrite pathway. Thus we tested the hypothesis that acute dietary nitrate supplementation increases the compensatory vasodilator response to hypoxic exercise, particularly in older adults. Thirteen young (25 ± 1 yr) and 12 older (64 ± 2 yr) adults performed rhythmic forearm exercise at 20% of maximum voluntary contraction during normoxia and hypoxia (∼80% O2 saturation); both before (control) and 3 h after beetroot juice (BR) consumption. Forearm vascular conductance (FVC; ml·min(-1)·100 mmHg(-1)) was calculated from forearm blood flow (ml/min) and blood pressure (mmHg). Compensatory vasodilation was defined as the relative increase in FVC due to hypoxic exercise (i.e., % increase compared with respective normoxic exercise trial). Plasma nitrite was determined from venous blood samples obtained before the control trials and each of the exercise trials (normoxia and hypoxia) after BR. Consumption of BR increased plasma nitrite in both young and older adults (P < 0.001). During the control condition, the compensatory vasodilator response to hypoxic exercise was attenuated in older compared with young adults (3.8 ± 1.7% vs. 14.2 ± 1.2%, P < 0.001). Following BR consumption, compensatory vasodilation did not change in young (13.7 ± 3.3%, P = 0.81) adults but was substantially augmented in older adults (11.4 ± 2.1%, P < 0.01). Our data suggest that acute dietary nitrate supplementation increases the compensatory vasodilator response to hypoxic exercise in older but not young adults.
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Affiliation(s)
- Darren P Casey
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa, Iowa City, Iowa; and
| | - David P Treichler
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa, Iowa City, Iowa; and
| | - Charles T Ganger
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa, Iowa City, Iowa; and
| | - Aaron C Schneider
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa, Iowa City, Iowa; and
| | - Kenichi Ueda
- Department of Anesthesia, Carver College of Medicine, University of Iowa, Iowa City, Iowa
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Elliott JE, Friedman JM, Futral JE, Goodman RD, Lovering AT. Sildenafil, nifedipine and acetazolamide do not allow for blood flow through intrapulmonary arteriovenous anastomoses during exercise while breathing 100% oxygen. Exp Physiol 2014; 99:1636-47. [DOI: 10.1113/expphysiol.2014.081562] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Kim JK, Moore DJ, Maurer DG, Kim-Shapiro DB, Basu S, Flanagan MP, Skulas-Ray AC, Kris-Etherton P, Proctor DN. Acute dietary nitrate supplementation does not augment submaximal forearm exercise hyperemia in healthy young men. Appl Physiol Nutr Metab 2014; 40:122-8. [PMID: 25536008 DOI: 10.1139/apnm-2014-0228] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Despite the popularity of dietary nitrate supplementation and the growing evidence base of its potential ergogenic and vascular health benefits, there is no direct information about its effects on exercising limb blood flow in humans. We hypothesized that acute dietary nitrate supplementation from beetroot juice would augment the increases in forearm blood flow, as well as the progressive dilation of the brachial artery, during graded handgrip exercise in healthy young men. In a randomized, double-blind, placebo-controlled crossover study, 12 young (22 ± 2 years) healthy men consumed a beetroot juice (140 mL Beet-It Sport, James White Juice Company) that provided 12.9 mmol (0.8 g) of nitrate or placebo (nitrate-depleted Beet-It Sport) on 2 study visits. At 3 h postconsumption, brachial artery diameter, flow, and blood velocity were measured (Doppler ultrasound) at rest and during 6 exercise intensities. Nitrate supplementation raised plasma nitrate (19.5-fold) and nitrite (1.6-fold) concentrations, and lowered resting arterial pulse wave velocity (PWV) versus placebo (all p < 0.05), indicating absorption, conversion, and a biological effect of this supplement. The supplement-associated lowering of PWV was also negatively correlated with plasma nitrite (r = -0.72, p = 0.0127). Despite these systemic effects, nitrate supplementation had no effect on brachial artery diameter, flow, or shear rates at rest (all p ≥ 0.28) or during any exercise workload (all p ≥ 0.18). These findings suggest that acute dietary nitrate supplementation favorably modifies arterial PWV, but does not augment blood flow or brachial artery vasodilation during nonfatiguing forearm exercise in healthy young men.
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Affiliation(s)
- Jin-Kwang Kim
- a Intercollege Graduate Degree Program in Physiology, The Pennsylvania State University, University Park, PA 16802, USA
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Billaut F, Aughey RJ. Update in the understanding of altitude-induced limitations to performance in team-sport athletes. Br J Sports Med 2014; 47 Suppl 1:i22-5. [PMID: 24282202 PMCID: PMC3903141 DOI: 10.1136/bjsports-2013-092834] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The internationalism of field-based team sports (TS) such as football and rugby requires teams to compete in tournaments held at low to moderate altitude (∼1200–2500 m). In TS, acceleration, speed and aerobic endurance are physical characteristics associated with ball possession and, ultimately, scoring. While these qualities are affected by the development of neuromuscular fatigue at sea level, arterial hypoxaemia induced by exposure to altitude may further hinder the capacity to perform consecutive accelerations (CAC) or sprint endurance and thereby change the outcome of a match. The higher the altitude, the more severe the hypoxaemia, and thus, the larger the expected decline in aerobic endurance, CAC and match running performance. Therefore, it is critical for athletes and coaches to understand how arterial hypoxaemia affects aerobic endurance and CAC and the magnitude of decline they may face at altitude for optimal preparation and increased chances of success. This mini review summarises the effects of acute altitude/hypoxia exposure on aerobic endurance, CAC and activity profiles of TS athletes performing in the laboratory and during matches at natural altitude, and analyses the latest findings about the consequences of arterial hypoxaemia on the relationship between peripheral perturbations, neural adjustments and performance during repeated sprints or CAC. Finally, we briefly discuss how altitude training can potentially help athletes prepare for competition at altitude.
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Affiliation(s)
- François Billaut
- Institut national du sport du Québec, , Montréal, Québec, Canada
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Bentley RF, Kellawan JM, Moynes JS, Poitras VJ, Walsh JJ, Tschakovsky ME. Individual susceptibility to hypoperfusion and reductions in exercise performance when perfusion pressure is reduced: evidence for vasodilator phenotypes. J Appl Physiol (1985) 2014; 117:392-405. [PMID: 24970851 DOI: 10.1152/japplphysiol.01155.2013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The primary objective of this study was to determine whether cardiovascular compensatory response phenotypes exist in the face of a reduced perfusion pressure challenge to exercising muscle oxygen delivery (O2D), and whether these responses might be exercise intensity (EI) dependent. Ten healthy men (19.5 ± 0.4 yr) completed two trials of progressive forearm isometric handgrip exercise to exhaustion (24.5 N increments every 3.5 min) in each of forearm above and below heart level [forearm arterial perfusion pressure (FAPP) difference of 29.5 ± 0.97 mmHg]. At the end of each EI, measurements of forearm blood flow (FBF; ml/min) via brachial artery Doppler and echo ultrasound, mean arterial blood pressure (MAP; mmHg) via finger photoplethysmography, and exercising forearm venous effluent via antecubital vein catheter revealed distinct cardiovascular response groups: n = 6 with compensatory vasodilation vs. n = 4 without compensatory vasodilation. Compensatory vasodilators were able to blunt the perfusion pressure-evoked reduction in submaximal O2D in the arm-above-heart condition, whereas nonvasodilators did not (-22.5 ± 13.6 vs. -65.4 ± 14.1 ml O2/min; P < 0.05), and in combination with being able to increase O2 extraction, nonvasodilators defended submaximal V̇o2 and experienced less of an accumulated submaximal O2D deficit (-80.7 ± 24.7 vs. -219.1 ± 36.0 ml O2/min; P < 0.05). As a result, the compensatory vasodilators experienced less of a compromise to peak EI than nonvasodilators (-24.5 ± 3.5 N vs. -52.1 ± 8.9 N; P < 0.05). In conclusion, in the forearm exercise model studied, vasodilatory response phenotypes exist that determine individual susceptibility to hypoperfusion and the degree to which aerobic metabolism and exercise performance are compromised.
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Affiliation(s)
- Robert F Bentley
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
| | - J Mikhail Kellawan
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
| | - Jackie S Moynes
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
| | - Veronica J Poitras
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
| | - Jeremy J Walsh
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
| | - Michael E Tschakovsky
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
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