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Zarębska EA, Kusy K, Korman P, Słomińska EM, Zieliński J. Exercise-induced changes in lower limbs skin temperature against plasma ATP among individuals with various type and level of physical activity. J Therm Biol 2024; 122:103877. [PMID: 38850622 DOI: 10.1016/j.jtherbio.2024.103877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 05/24/2024] [Accepted: 05/27/2024] [Indexed: 06/10/2024]
Abstract
The objective of the study was to examine the lower limbs skin temperature (TSK) changes in response to exhaustive whole-body exercise in trained individuals in reference to changes in plasma adenosine triphosphate (ATP). Eighteen trained participants from distinct sport type ‒ endurance (25.2 ± 4.9 yr) and speed-power (25.8 ± 3.1 yr), and 9 controls (24,9 ± 4,3 yr) ‒ were examined. Lower limbs TSK and plasma ATP measures were applied in parallel in response to incremental treadmill test and during 30-min recovery period. Plasma ATP kinetics were inversely associated to changes in TSK. The first significant decrease in TSK (76-89% of V˙ O2MAX) occurred shortly before a significant plasma ATP increase (86-97% of V˙ O2MAX). During recovery, TSK increased, reaching pre-exercise values (before exercise vs. after 30-min recovery: 31.6 ± 0.4 °C vs. 32.0 ± 0.8 °C, p = 0.855 in endurance; 32.4 ± 0.5 °C vs. 32.9 ± 0.5 °C, p = 0.061 in speed-power; 31.9 ± 0.7 °C vs. 32.4 ± 0.8 °C, p = 0.222 in controls). Plasma ATP concentration did not returned to pre-exercise values in well trained participants (before exercise vs. after 30-min recovery: 699 ± 57 nmol l-1 vs. 854 ± 31 nmol l-1, p < 0.001, η2 = 0.961 and 812 ± 35 nmol l-1 vs. 975 ± 55 nmol l-1, p < 0.001, η2 = 0.974 in endurance and speed-power, respectively), unlike in controls (651 ± 40 nmol l-1 vs. 687 ± 61 nmol·l-1, p = 0.58, η2 = 0.918). The magnitude of TSK and plasma ATP response differed between the groups (p < 0.001, η2 = 0.410 for TSK; p < 0.001, η2 = 0.833 for plasma ATP). We conclude that lower limbs TSK change indirectly corresponds to the reverse course of plasma ATP during incremental exercise and the magnitude of the response depends on the level of physical activity and the associated to it long-term metabolic adaptation.
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Affiliation(s)
- Ewa A Zarębska
- Department of Athletics, Strength and Conditioning, Poznan University of Physical Education, 61-871, Poznan, Poland.
| | - Krzysztof Kusy
- Department of Athletics, Strength and Conditioning, Poznan University of Physical Education, 61-871, Poznan, Poland.
| | - Paweł Korman
- Department of Physical Therapy and Sports Recovery, Poznan University of Physical Education, 61-871, Poznan, Poland.
| | - Ewa M Słomińska
- Department of Biochemistry, Medical University of Gdansk, 80-211, Gdansk, Poland.
| | - Jacek Zieliński
- Department of Athletics, Strength and Conditioning, Poznan University of Physical Education, 61-871, Poznan, Poland.
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Deming N, Steer S, Hernandez J, Dinenno F, Richards J. Carbohydrate ingestion attenuates the reduction in complex cognitive function and cerebral blood flow during prolonged passive heat stress in humans. J Therm Biol 2023; 117:103698. [PMID: 37734348 DOI: 10.1016/j.jtherbio.2023.103698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 08/07/2023] [Accepted: 08/23/2023] [Indexed: 09/23/2023]
Abstract
PURPOSE To determine whether carbohydrate ingestion would reduce cognitive dysfunction in humans following long duration passive heat stress (PHS) versus consuming electrolytes alone. METHODS Fifteen young (27 ± 4 y) healthy adults were exposed to 120 min of PHS through the use of a liquid perfused suit (50 °C) on two randomized visits. Subjects consumed fluids supplemented with electrolytes (E) or electrolytes + carbohydrates (E + C). Pre- and post-heat stress, body mass (BM) and plasma osmolality (pOsm) were measured. Heart rate (HR), blood pressure (BP), Physiological Strain Index (PSI), core temperature (Tc), plasma glucose, respiration rate (RR), end-tidal CO2 (PetCO2) and internal carotid artery (ICA) blood flow were recorded at baseline and every 15 min of heat stress. Cognitive function was assessed via the Automated Neuropsychological Assessment Metric at baseline and at 30- and 120 min during heat stress. RESULTS There were no significant differences between fluid conditions for BM, pOsm, PSI, Tc, RR or PetCO2. Plasma glucose was ∼75% greater in the E + C condition compared to the E condition after 90 min of PHS (P < 0.05). Cognitive function (120 min) was impaired following PHS only in E condition (P < 0.05) and performance on complex cognitive tasks were better by ∼22-340% in the E + C vs. E (P < 0.05). Compared to the E condition, HR and BP were lower and ICA blood flow, vascular conductance, and glucose delivery was ∼90% greater in the E + C after 90 min of PHS (P < 0.05). CONCLUSIONS These data are the first to demonstrate that carbohydrate ingestion may have a protective effect on cognitive function during long duration PHS. Furthermore, this protection was associated with preserved ICA blood flow and glucose delivery to the brain.
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Affiliation(s)
- Nathan Deming
- Human Performance Laboratory, Directorate of Athletics, USAF Academy, CO, 80840, USA; Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, 80521, USA
| | - Sarah Steer
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, 80521, USA
| | - Jesse Hernandez
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, 80521, USA
| | - Frank Dinenno
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, 80521, USA
| | - Jennifer Richards
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, 80521, USA.
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Rivers RJ, Meininger CJ. The Tissue Response to Hypoxia: How Therapeutic Carbon Dioxide Moves the Response toward Homeostasis and Away from Instability. Int J Mol Sci 2023; 24:ijms24065181. [PMID: 36982254 PMCID: PMC10048965 DOI: 10.3390/ijms24065181] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 03/02/2023] [Accepted: 03/05/2023] [Indexed: 03/30/2023] Open
Abstract
Sustained tissue hypoxia is associated with many pathophysiological conditions, including chronic inflammation, chronic wounds, slow-healing fractures, microvascular complications of diabetes, and metastatic spread of tumors. This extended deficiency of oxygen (O2) in the tissue sets creates a microenvironment that supports inflammation and initiates cell survival paradigms. Elevating tissue carbon dioxide levels (CO2) pushes the tissue environment toward "thrive mode," bringing increased blood flow, added O2, reduced inflammation, and enhanced angiogenesis. This review presents the science supporting the clinical benefits observed with the administration of therapeutic CO2. It also presents the current knowledge regarding the cellular and molecular mechanisms responsible for the biological effects of CO2 therapy. The most notable findings of the review include (a) CO2 activates angiogenesis not mediated by hypoxia-inducible factor 1a, (b) CO2 is strongly anti-inflammatory, (c) CO2 inhibits tumor growth and metastasis, and (d) CO2 can stimulate the same pathways as exercise and thereby, acts as a critical mediator in the biological response of skeletal muscle to tissue hypoxia.
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Affiliation(s)
- Richard J Rivers
- Department of Anesthesia and Critical Care Medicine, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Cynthia J Meininger
- Department of Medical Physiology, Texas A&M University School of Medicine, Bryan, TX 77807, USA
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Domin R, Pytka M, Niziński J, Żołyński M, Zybek-Kocik A, Wrotkowska E, Zieliński J, Guzik P, Ruchała M. ATPase Inhibitory Factor 1-A Novel Marker of Cellular Fitness and Exercise Capacity? Int J Mol Sci 2022; 23:15303. [PMID: 36499630 PMCID: PMC9741029 DOI: 10.3390/ijms232315303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 11/26/2022] [Accepted: 12/01/2022] [Indexed: 12/12/2022] Open
Abstract
ATPase inhibitory factor 1 is a myokine inhibiting the hydrolytic activity of mitochondrial adenosine triphosphate synthase and ecto-F1-ATPase on the surface of many cells. IF1 affects ATP metabolism in mitochondria and the extracellular space and upregulates glucose uptake in myocytes; these processes are essential in physical activity. It is unknown whether the IF1 serum concentration is associated with exercise capacity. This study explored the association between resting IF1 serum concentration and exercise capacity indices in healthy people. IF1 serum concentration was measured in samples collected at rest in 97 healthy amateur cyclists. Exercise capacity was assessed on a bike ergometer at the successive stages of the progressive cardiopulmonary exercise test (CPET). IF1 serum concentration was negatively and significantly correlated with oxygen consumption, oxygen pulse, and load at various CPET stages. A better exercise capacity was associated with lower circulating IF1. IF1 may reflect better cellular/mitochondrial energetic fitness, but there is uncertainty regarding how IF1 is released into the intravascular space. We speculate that lower IF1 concentration may reflect a better cellular/mitochondrial integrity, as this protein is bound more strongly with ATPases in mitochondria and cellular surfaces in people with higher exercise capacity.
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Affiliation(s)
- Remigiusz Domin
- Department of Endocrinology, Metabolism and Internal Medicine, Poznan University of Medical Sciences, 60-355 Poznan, Poland
- University Centre for Sport and Medical Studies, Poznan University of Medical Sciences, 60-802 Poznan, Poland
| | - Michał Pytka
- University Centre for Sport and Medical Studies, Poznan University of Medical Sciences, 60-802 Poznan, Poland
- Department of Cardiology, Intensive Therapy, Poznan University of Medical Sciences, 60-355 Poznan, Poland
| | - Jan Niziński
- University Centre for Sport and Medical Studies, Poznan University of Medical Sciences, 60-802 Poznan, Poland
| | - Mikołaj Żołyński
- University Centre for Sport and Medical Studies, Poznan University of Medical Sciences, 60-802 Poznan, Poland
| | - Ariadna Zybek-Kocik
- Department of Endocrinology, Metabolism and Internal Medicine, Poznan University of Medical Sciences, 60-355 Poznan, Poland
| | - Elżbieta Wrotkowska
- Department of Endocrinology, Metabolism and Internal Medicine, Poznan University of Medical Sciences, 60-355 Poznan, Poland
| | - Jacek Zieliński
- Department of Athletics, Strength and Conditioning, Poznan University of Physical Education, 61-871 Poznan, Poland
| | - Przemysław Guzik
- University Centre for Sport and Medical Studies, Poznan University of Medical Sciences, 60-802 Poznan, Poland
- Department of Cardiology, Intensive Therapy, Poznan University of Medical Sciences, 60-355 Poznan, Poland
| | - Marek Ruchała
- Department of Endocrinology, Metabolism and Internal Medicine, Poznan University of Medical Sciences, 60-355 Poznan, Poland
- University Centre for Sport and Medical Studies, Poznan University of Medical Sciences, 60-802 Poznan, Poland
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Racine ML, Terwoord JD, Ketelhut NB, Bachman NP, Richards JC, Luckasen GJ, Dinenno FA. Rho-kinase inhibition improves haemodynamic responses and circulating ATP during hypoxia and moderate intensity handgrip exercise in healthy older adults. J Physiol 2022; 600:3265-3285. [PMID: 35575293 PMCID: PMC9288513 DOI: 10.1113/jp282730] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Accepted: 05/09/2022] [Indexed: 11/21/2022] Open
Abstract
Abstract Skeletal muscle haemodynamics and circulating adenosine triphosphate (ATP) responses during hypoxia and exercise are blunted in older (OA) vs. young (YA) adults, which may be associated with impaired red blood cell (RBC) ATP release. Rho‐kinase inhibition improves deoxygenation‐induced ATP release from OA isolated RBCs. We tested the hypothesis that Rho‐kinase inhibition (via fasudil) in vivo would improve local haemodynamic and ATP responses during hypoxia and exercise in OA. Healthy YA (25 ± 3 years; n = 12) and OA (65 ± 5 years; n = 13) participated in a randomized, double‐blind, placebo‐controlled, crossover study on two days (≥5 days between visits). A forearm deep venous catheter was used to administer saline/fasudil and sample venous plasma ATP ([ATP]V). Forearm vascular conductance (FVC) and [ATP]V were measured at rest, during isocapnic hypoxia (80% SpO2), and during graded rhythmic handgrip exercise that was similar between groups (5, 15 and 25% maximum voluntary contraction (MVC)). Isolated RBC ATP release was measured during normoxia/hypoxia. With saline, ΔFVC was lower (P < 0.05) in OA vs. YA during hypoxia (∼60%) and during 15 and 25% MVC (∼25–30%), and these impairments were abolished with fasudil. Similarly, [ATP]V and ATP effluent responses from normoxia to hypoxia and rest to 25% MVC were lower in OA vs. YA and improved with fasudil (P < 0.05). Isolated RBC ATP release during hypoxia was impaired in OA vs. YA (∼75%; P < 0.05), which tended to improve with fasudil in OA (P = 0.082). These data suggest Rho‐kinase inhibition improves haemodynamic responses to hypoxia and moderate intensity exercise in OA, which may be due in part to improved circulating ATP.
![]() Key points Skeletal muscle blood flow responses to hypoxia and exercise are impaired with age. Blunted increases in circulating ATP, a vasodilator, in older adults may contribute to age‐related impairments in haemodynamics. Red blood cells (RBCs) are a primary source of circulating ATP, and treating isolated RBCs with a Rho‐kinase inhibitor improves age‐related impairments in deoxygenation‐induced RBC ATP release. In this study, treating healthy older adults systemically with the Rho‐kinase inhibitor fasudil improved blood flow and circulating ATP responses during hypoxia and moderate intensity handgrip exercise compared to young adults, and also tended to improve isolated RBC ATP release. Improved blood flow regulation with fasudil was also associated with increased skeletal muscle oxygen delivery during hypoxia and exercise in older adults. This is the first study to demonstrate that Rho‐kinase inhibition can significantly improve age‐related impairments in haemodynamic and circulating ATP responses to physiological stimuli, which may have therapeutic implications.
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Affiliation(s)
- Matthew L Racine
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, 80523, USA
| | - Janée D Terwoord
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, 80523, USA
| | - Nathaniel B Ketelhut
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, 80523, USA
| | - Nate P Bachman
- 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
| | - Gary J Luckasen
- Medical Center of the Rockies, University of Colorado Health, Loveland, CO, 80538, USA
| | - Frank A Dinenno
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, 80523, USA
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Keller JL, Kennedy KG, Hill EC, Fleming SR, Colquhoun RJ, Schwarz NA. Handgrip exercise induces sex-specific mean arterial pressure and oxygenation responses but similar performance fatigability. Clin Physiol Funct Imaging 2022; 42:127-138. [PMID: 34979052 DOI: 10.1111/cpf.12739] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Revised: 10/30/2021] [Accepted: 12/20/2021] [Indexed: 01/19/2023]
Abstract
Women exhibit an attenuated exercise pressor reflex (EPR) when compared to men. The influence of sex-specific mechanisms related to the EPR and performance fatigability remain to be fully elucidated. The purpose was to determine the impact of oxygenation and metabolic efficiency on sex-specific performance fatigability and increases in mean arterial pressure (MAP) resulting from a fatiguing isometric handgrip (IHG). Twenty-four adults volunteered to perform an IHG at 25% at maximal voluntary isometric contractions (MVICs). Pre- and posttest MVICs were conducted to quantify performance fatigability. MAP was collected at 3 timepoints. A near-infrared spectroscopy device was attached to the forearm to derive the following signals: oxy[haem], deoxy[haem], total[haem], and diff[haem]. These values were normalized and examined across time in 5% segments of time-to-task-failure. Metabolic efficiency was defined as the ratio force:deoxy[haem]. During the IHG, there was a decline in oxy[haem] for the men (b = -0.075), whereas the women demonstrated an increase (b = 0.117). For the men, the diff[haem] tracked the mean oxy[haem] response, but there was no change for the women. The men exhibited greater declines in metabolic efficiency, yet there were no sex differences in PF (46.6 ± 9.7% vs. 45.5 ± 14.2%). For relative MAP, the men (24.5 ± 15.1%) exhibited a greater (p = .03) increase than the women (11.0 ± 17.6%). These results indicated the EPR was more prominent for the men, perhaps due to differences in mechanical stimuli and a lack of ability to maintain metabolic efficiency. However, these physiological differences did not induce a sex difference in performance fatigability.
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Affiliation(s)
- Joshua L Keller
- Department of Health, Kinesiology, and Sport, College of Education and Professional Studies, University of South Alabama, Mobile, Alabama, USA
| | - Katie G Kennedy
- Department of Health, Kinesiology, and Sport, College of Education and Professional Studies, University of South Alabama, Mobile, Alabama, USA
| | - Ethan C Hill
- Division of Kinesiology, School of Kinesiology and Physical Therapy, University of Central Florida, Orlando, Florida, USA.,Florida Space Institute, University of Central Florida, Orlando, Florida, USA
| | - Sydnie R Fleming
- Department of Health, Kinesiology, and Sport, College of Education and Professional Studies, University of South Alabama, Mobile, Alabama, USA
| | - Ryan J Colquhoun
- Department of Health, Kinesiology, and Sport, College of Education and Professional Studies, University of South Alabama, Mobile, Alabama, USA
| | - Neil A Schwarz
- Department of Health, Kinesiology, and Sport, College of Education and Professional Studies, University of South Alabama, Mobile, Alabama, USA
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Kirby BS, Sparks MA, Lazarowski ER, Lopez Domowicz DA, Zhu H, McMahon TJ. Pannexin 1 channels control the hemodynamic response to hypoxia by regulating O 2-sensitive extracellular ATP in blood. Am J Physiol Heart Circ Physiol 2021; 320:H1055-H1065. [PMID: 33449849 PMCID: PMC7988759 DOI: 10.1152/ajpheart.00651.2020] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 01/07/2021] [Accepted: 01/07/2021] [Indexed: 12/23/2022]
Abstract
Pannexin 1 (Panx1) channels export ATP and may contribute to increased concentration of the vasodilator ATP in plasma during hypoxia in vivo. We hypothesized that Panx1 channels and associated ATP export contribute to hypoxic vasodilation, a mechanism that facilitates the matching of oxygen delivery to metabolic demand of tissue. Male and female mice devoid of Panx1 (Panx1-/-) and wild-type controls (WT) were anesthetized, mechanically ventilated, and instrumented with a carotid artery catheter or femoral artery flow transducer for hemodynamic and plasma ATP monitoring during inhalation of 21% (normoxia) or 10% oxygen (hypoxia). ATP export from WT vs. Panx1-/-erythrocytes (RBC) was determined ex vivo via tonometer experimentation across progressive deoxygenation. Mean arterial pressure (MAP) was similar in Panx1-/- (n = 6) and WT (n = 6) mice in normoxia, but the decrease in MAP in hypoxia seen in WT was attenuated in Panx1-/- mice (-16 ± 9% vs. -2 ± 8%; P < 0.05). Hindlimb blood flow (HBF) was significantly lower in Panx1-/- (n = 6) vs. WT (n = 6) basally, and increased in WT but not Panx1-/- mice during hypoxia (8 ± 6% vs. -10 ± 13%; P < 0.05). Estimation of hindlimb vascular conductance using data from the MAP and HBF experiments showed an average response of 28% for WT vs. -9% for Panx1-/- mice. Mean venous plasma ATP during hypoxia was 57% lower in Panx1-/- (n = 6) vs. WT mice (n = 6; P < 0.05). Mean hypoxia-induced ATP export from RBCs from Panx1-/- mice (n = 8) was 82% lower than that from WT (n = 8; P < 0.05). Panx1 channels participate in hemodynamic responses consistent with hypoxic vasodilation by regulating hypoxia-sensitive extracellular ATP levels in blood.NEW & NOTEWORTHY Export of vasodilator ATP from red blood cells requires pannexin 1. Blood plasma ATP elevations in response to hypoxia in mice require pannexin 1. Hemodynamic responses to hypoxia are accompanied by increased plasma ATP in mice in vivo and require pannexin 1.
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Affiliation(s)
- Brett S Kirby
- Division of Hematology, Department of Medicine, Duke University Medical Center, Durham, North Carolina
| | - Matthew A Sparks
- Division of Nephrology, Department of Medicine, Duke University Medical Center, Durham, North Carolina
- Departments of Medicine and Research and Development, Durham Veterans Affairs Medical Center, Durham, North Carolina
| | - Eduardo R Lazarowski
- Department of Medicine, Marsico Lung Institute/UNC Cystic Fibrosis Research Center, University of North Carolina, Chapel Hill, North Carolina
| | - Denise A Lopez Domowicz
- Division of Critical Care Medicine, Department of Pediatrics, Duke University Medical Center, Durham, North Carolina
| | - Hongmei Zhu
- Division of Pulmonary, Allergy, Critical Care Medicine, Department of Medicine, Duke University Medical Center, Durham, North Carolina
| | - Timothy J McMahon
- Department of Medicine, Marsico Lung Institute/UNC Cystic Fibrosis Research Center, University of North Carolina, Chapel Hill, North Carolina
- Division of Pulmonary, Allergy, Critical Care Medicine, Department of Medicine, Duke University Medical Center, Durham, North Carolina
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Su D. Up-regulation of MiR-145-5p promotes the growth and migration in LPS-treated HUVECs through inducing macrophage polarization to M2. J Recept Signal Transduct Res 2020; 41:434-441. [PMID: 32998623 DOI: 10.1080/10799893.2020.1818095] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
MiR-145-5p is high-expressed in human vascular endothelial cells (HUVECs) and alternatively activated macrophages (M2). However, whether miR-145-5p can reduce HUVEC damage by regulating macrophage immunophenotype is less reported. THP-1 was stimulated by Phorbolate-12-myristate-13-acetate, LPS and IFN-γ, and IL-4 to differentiate into macrophages (M0, M1 and M2). The expressions of macrophage markers were detected by Western blotting, and the expressions of miR-145-5p and kruppel-like factor-14 (KLF14) were detected by qRT-PCR. Dual-luciferase reporter assay was used to analyze the targeted relationship of miR-145-5p and KLF14. HUVEC injury was induced by LPS and then co-cultured with M1 transfected by miR-145-5p mimic. The effect of miR-145-3p on proliferation and metastasis of LPS-induced HUVECs was detected by MTT, clone formation, scratch assay and Transwell. We found that the expression of miR-145-5p was higher in M2 than that in M1. MiR-145-5p expression was down-regulated during M2-to-M1, but up-regulated during M1-to-M2. The expressions of IL-1β and iNOS were down-regulated, while the protein expressions of CCL17 and Arg-1 were up-regulated by miR-145-5p mimic in M0. The viability, proliferation, migration and invasion of HUVECs were promoted, however, LDH activity of the HUVECs was inhibited by mimics. In addition, KLF14 was predicted as the target gene for miR-145-5p in HUVECs. Collectively, our results demonstrate that miR-145-5p inhibited cell proliferation of LPS-treated HUVECs possibly through regulating macrophage polarization to M2.
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Affiliation(s)
- Dongna Su
- Department of Infectious Diseases, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University; The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, Guangdong, China
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Sabouhanian A, Ameri S. Elucidating the role of K IR channels in rapid vasodilatation during transition in exercise intensity and different levels of muscle fibre recruitment. J Physiol 2020; 598:4451-4453. [PMID: 32715481 DOI: 10.1113/jp280187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 06/23/2020] [Indexed: 11/08/2022] Open
Affiliation(s)
- Amir Sabouhanian
- Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
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10
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Zhao Y, Huang G, Chen Z, Fan X, Huang T, Liu J, Zhang Q, Shen J, Li Z, Shi Y. Four Loci Are Associated with Cardiorespiratory Fitness and Endurance Performance in Young Chinese Females. Sci Rep 2020; 10:10117. [PMID: 32572135 PMCID: PMC7723046 DOI: 10.1038/s41598-020-67045-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 06/01/2020] [Indexed: 12/26/2022] Open
Abstract
Cardiorespiratory fitness (CRF) and endurance performance are characterized by a complex genetic trait with high heritability. Although research has identified many physiological and environmental correlates with CRF, the genetic architecture contributing to CRF remains unclear, especially in non-athlete population. A total of 762 Chinese young female participants were recruited and an endurance run test was used to determine CRF. We used a fixed model of genome-wide association studies (GWAS) for CRF. Genotyping was performed using the Affymetrix Axiom and illumina 1 M arrays. After quality control and imputation, a linear regression-based association analysis was conducted using a total of 5,149,327 variants. Four loci associated with CRF were identified to reach genome-wide significance (P < 5.0 × 10-8), which located in 15q21.3 (rs17240160, P = 1.73 × 10-9, GCOM1), 3q25.31 (rs819865, P = 8.56 × 10-9, GMPS), 21q22.3 (rs117828698, P = 9.59 × 10-9, COL18A1), and 17q24.2 (rs79806428, P = 3.85 × 10-8, PRKCA). These loci (GCOM1, GMPS, COL18A1 and PRKCA) associated with cardiorespiratory fitness and endurance performance in Chinese non-athlete young females. Our results suggest that these gene polymorphisms provide further genetic evidence for the polygenetic nature of cardiorespiratory endurance and be used as genetic biomarkers for future research.
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Affiliation(s)
- Ying Zhao
- Physical Education Department, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Guoyuan Huang
- Pott College of Science, Engineering and Education, University of Southern Indiana, Indiana, 47712, USA
| | - Zuosong Chen
- Physical Education Department, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Xiang Fan
- Physical Education Department, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Tao Huang
- Physical Education Department, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Jinsheng Liu
- School Infirmary, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Qing Zhang
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Jingyi Shen
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Zhiqiang Li
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai, 200240, China. .,Affiliated Hospital of Qingdao University, Qingdao, 266003, China. .,Biomedical Sciences Institute of Qingdao University (Qingdao Branch of SJTU Bio-X Institutes), Qingdao University, Qingdao, 266003, China.
| | - Yongyong Shi
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai, 200240, China. .,Biomedical Sciences Institute of Qingdao University (Qingdao Branch of SJTU Bio-X Institutes), Qingdao University, Qingdao, 266003, China. .,Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200030, China. .,Department of Psychiatry, First Teaching Hospital of Xinjiang Medical University, Urumqi, 830046, China.
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11
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Terwoord JD, Hearon CM, Racine ML, Ketelhut NB, Luckasen GJ, Richards JC, Dinenno FA. K IR channel activation links local vasodilatation with muscle fibre recruitment during exercise in humans. J Physiol 2020; 598:2621-2636. [PMID: 32329892 DOI: 10.1113/jp279682] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Accepted: 04/17/2020] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS During exercise, blood flow to working skeletal muscle increases in parallel with contractile activity such that oxygen delivery is sufficient to meet metabolic demand. K+ released from active skeletal muscle fibres could facilitate vasodilatation in proportion to the degree of muscle fibre recruitment. Once released, K+ stimulates inwardly rectifying K+ (KIR ) channels on the vasculature to elicit an increase in blood flow. In the present study, we demonstrate that KIR channels mediate the rapid vasodilatory response to an increase in exercise intensity. We also show that KIR channels augment vasodilatation during exercise which demands greater muscle fibre recruitment independent of the total amount of work performed. These results suggest that K+ plays a key role in coupling the magnitude of vasodilatation to the degree of contractile activity. Ultimately, the findings from this study help us understand the signalling mechanisms that regulate muscle blood flow in humans. ABSTRACT Blood flow to active skeletal muscle is augmented with greater muscle fibre recruitment. We tested whether activation of inwardly rectifying potassium (KIR ) channels underlies vasodilatation with elevated muscle fibre recruitment when work rate is increased (Protocol 1) or held constant (Protocol 2). We assessed forearm vascular conductance (FVC) during rhythmic handgrip exercise under control conditions and during local inhibition of KIR channels (intra-arterial BaCl2 ). In Protocol 1, healthy volunteers performed mild handgrip exercise for 3 min, then transitioned to moderate intensity for 30 s. BaCl2 eliminated vasodilatation during the first contraction at the moderate workload (ΔFVC, BaCl2 : -1 ± 17 vs. control: 30 ± 28 ml min-1 100 mmHg-1 ; n = 9; P = 0.004) and attenuated the 30 s area under the curve by 56 ± 14% (n = 9; P < 0.0001). In Protocol 2, participants performed two exercise bouts in which muscle fibre recruitment was manipulated while total contractile work was held constant via reciprocal changes in contraction frequency: (1) low fibre recruitment, with contractions at 12.5% maximal voluntary contraction once every 4 s and (2) high fibre recruitment, with contractions at 25% maximal voluntary contraction once every 8 s. Under control conditions, steady-state FVC was augmented in high vs. low fibre recruitment (211 ± 90 vs. 166 ± 73 ml min-1 ⋅100 mmHg-1 ; n = 10; P = 0.0006), whereas BaCl2 abolished the difference between high and low fibre recruitment (134 ± 59 vs. 134 ± 63 ml min-1 100 mmHg-1 ; n = 10; P = 0.85). These findings demonstrate that KIR channel activation is a key mechanism linking local vasodilatation with muscle fibre recruitment during exercise.
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Affiliation(s)
- Janée D Terwoord
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
| | - Christopher M Hearon
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
| | - Matthew L Racine
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
| | - Nathaniel B Ketelhut
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
| | - Gary J Luckasen
- Medical Center of the Rockies Foundation, University of Colorado Health, Loveland, CO, USA
| | - Jennifer C Richards
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
| | - Frank A Dinenno
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
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12
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Hearon CM, Richards JC, Racine ML, Luckasen GJ, Larson DG, Dinenno FA. Augmentation of endothelium-dependent vasodilatory signalling improves functional sympatholysis in contracting muscle of older adults. J Physiol 2020; 598:2323-2336. [PMID: 32306393 DOI: 10.1113/jp279462] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 04/14/2020] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS The ability of contracting skeletal muscle to attenuate sympathetic vasoconstriction (functional sympatholysis) is critical for maintaining blood flow during exercise-mediated sympathoexcitation. Functional sympatholysis and endothelial function are impaired with ageing, resulting in compromised blood flow and oxygen delivery to contracting skeletal muscle during exercise. In the present study, intra-arterial infusion of ACh or ATP to augment endothelium-dependent signalling during exercise attenuated α1 -adrenergic vasoconstriction in the contracting muscle of older adults. The vascular signalling mechanisms capable of functional sympatholysis are preserved in healthy ageing, and thus the age-related impairment in functional sympatholysis probably results from the loss of a functional signal (e.g. plasma [ATP]) as opposed to an intrinsic endothelial dysfunction. ABSTRACT The ability of contracting skeletal muscle to attenuate sympathetic α-adrenergic vasoconstriction ('functional sympatholysis') is impaired with age. In young adults, increasing endothelium-dependent vasodilatory signalling during mild exercise augments sympatholysis. In the present study, we tested the hypothesis that increasing endothelium-dependent signalling during exercise in older adults can improve sympatholysis. In 16 older individuals (Protocol 1, n = 8; Protocol 2, n = 8), we measured forearm blood flow (Doppler ultrasound) and calculated changes in vascular conductance (FVC) to local intra-arterial infusion of phenylephrine (PE; α1 -agonist) during (i) infusion of an endothelium-dependent vasodilator alone (Protocol 1: ACh or Protocol 2: low dose ATP); (ii) mild handgrip exercise (5% maximum voluntary contraction; MVC); (iii) moderate handgrip exercise (15% MVC); and (iv) mild or moderate handgrip exercise + infusion of ACh or ATP to augment endothelium-dependent signalling. PE caused robust vasoconstriction in resting skeletal muscle during control vasodilator infusions (ΔFVC: ACh: -31 ± 3 and ATP: -30 ± 4%). PE-mediated vasoconstriction was not attenuated by mild or moderate intensity exercise (ΔFVC: 5% MVC: -30 ± 9; 15% MVC: -33 ± 8%; P > 0.05 vs. control ACh and ATP), indicative of impaired sympatholysis, and ACh or ATP infusion during mild exercise did not impact this response. However, augmentation of endothelium-dependent signalling via infusion of ACh or ATP during moderate intensity exercise attenuated PE-mediated vasoconstriction (ΔFVC: -13 ± 1 and -19 ± 5%, respectively; P < 0.05 vs. all conditions). Our findings demonstrate that, given a sufficient stimulus, endothelium-dependent sympatholysis remains intact in older adults. Strategies aimed at activating such pathways represent a viable approach for improving sympatholysis and thus tissue blood flow and oxygen delivery in older adults.
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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, USA
| | - Jennifer C Richards
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
| | - Mathew L Racine
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
| | - Gary J Luckasen
- Medical Center of the Rockies Foundation, University of Colorado Health System, Loveland, CO, USA
| | - Dennis G Larson
- Medical Center of the Rockies Foundation, University of Colorado Health System, Loveland, CO, USA
| | - Frank A Dinenno
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA.,Center for Cardiovascular Research, Colorado State University, Fort Collins, CO, USA
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13
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Dillon GA, Shepherd JR, Casey DP, Dinenno FA, Curry TB, Joyner MJ, Ranadive SM. Rapid-onset vasodilator responses to exercise in humans: Effect of increased baseline blood flow. Exp Physiol 2020; 105:88-95. [PMID: 31762131 PMCID: PMC6938538 DOI: 10.1113/ep088227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 11/22/2019] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? What is the effect of an elevated baseline blood flow, induced by high-dose intra-arterial infusion of either adenosine or ATP, on the rapid-onset vasodilatory response to a single forearm muscle contraction? What is the main finding and its importance? The peak response to a single contraction is unaffected by augmented baseline blood flow, and thus, is likely to be attributable to a feedforward vasodilatory mechanism. ABSTRACT The hyperaemic responses to single muscle contractions are proportional to exercise intensity, which, in turn, is proportional to tissue metabolic demand. Hence, we tested the hypothesis that the rapid-onset vasodilatory response after a single muscle contraction would be unaffected when baseline blood flow was increased via high-dose intra-arterial infusion of either adenosine (ADO) or ATP. Twenty-four healthy young participants (28 ± 1 years) performed a single forearm contraction (20% maximal voluntary contraction) 75 min after commencement of a continuous infusion of ADO (n = 6), ATP (n = 8) or saline (control; n = 10). Brachial artery diameter and blood velocity were measured using Doppler ultrasound. Resting forearm vascular conductance (FVC; in millilitres per minute per 100 mmHg per decilitre of forearm volume) was significantly higher during ADO (33 ± 17) and ATP infusion (33 ± 17) compared with the control infusion (8 ± 3; P < 0.05). The peak FVCs post-contraction during ADO and ATP infusions were significantly greater than during the control infusion (P < 0.05), but not different from one another. The peak change in FVC from baseline was similar in all three conditions (control, 14 ± 1; ADO, 24 ± 2; and ATP, 23 ± 6; P = 0.15). Total FVC (area under the curve) did not differ significantly between ADO and ATP (333 ± 69 and 440 ± 125); however, total FVC during ATP infusion was significantly greater compared with the control value (150 ± 19; P < 0.05). We conclude that the peak response to a single contraction is unaffected by augmented baseline blood flow and is therefore likely to be attributable to a feedforward vasodilatory mechanism.
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Affiliation(s)
- Gabrielle A. Dillon
- Department of Anesthesiology, Mayo Clinic, Rochester, MN 55905 United States
| | - John R.A. Shepherd
- Department of Anesthesiology, Mayo Clinic, Rochester, MN 55905 United States
| | - Darren P. Casey
- Department of Physical Therapy and Rehabilitation Science, University of Iowa, Iowa City, IA 52242 United States
| | - Frank A. Dinenno
- Department of Health and Exercise Science, and Center for Cardiovascular Research, Colorado State University, Fort Collins, CO 80523 United States
| | - Timothy B. Curry
- Department of Anesthesiology, Mayo Clinic, Rochester, MN 55905 United States
| | - Michael J. Joyner
- Department of Anesthesiology, Mayo Clinic, Rochester, MN 55905 United States
| | - Sushant M. Ranadive
- Department of Anesthesiology, Mayo Clinic, Rochester, MN 55905 United States
- Department of Kinesiology, University of Maryland, College Park, MD 20742 United States
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14
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Racine ML, Dinenno FA. Reduced deformability contributes to impaired deoxygenation-induced ATP release from red blood cells of older adult humans. J Physiol 2019; 597:4503-4519. [PMID: 31310005 DOI: 10.1113/jp278338] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Accepted: 07/15/2019] [Indexed: 12/17/2022] Open
Abstract
KEY POINTS Red blood cells (RBCs) release ATP in response to deoxygenation, which can increase blood flow to help match oxygen supply with tissue metabolic demand. This release of ATP is impaired in RBCs from older adults, but the underlying mechanisms are unknown. In this study, improving RBC deformability in older adults restored deoxygenation-induced ATP release, whereas decreasing RBC deformability in young adults reduced ATP release to the level of that of older adults. In contrast, treating RBCs with a phosphodiesterase 3 inhibitor did not affect ATP release in either age group, possibly due to intact intracellular signalling downstream of deoxygenation as indicated by preserved cAMP and ATP release responses to pharmacological Gi protein activation in RBCs from older adults. These findings are the first to demonstrate that the age-related decrease in RBC deformability is a primary mechanism of impaired deoxygenation-induced ATP release, which may have implications for treating impaired vascular control with advancing age. ABSTRACT In response to haemoglobin deoxygenation, red blood cells (RBCs) release ATP, which binds to endothelial purinergic receptors and stimulates vasodilatation. This ATP release is impaired in RBCs from older vs. young adults, but the underlying mechanisms are unknown. Using isolated RBCs from young (24 ± 1 years) and older (65 ± 2 years) adults, we tested the hypothesis that age-related changes in RBC deformability (Study 1) and cAMP signalling (Study 2) contribute to the impairment. RBC ATP release during normoxia ( P O 2 ∼112 mmHg) and hypoxia ( P O 2 ∼20 mmHg) was quantified with the luciferin-luciferase technique following RBC incubation with Y-27632 (Rho-kinase inhibitor to increase deformability), diamide (cell-stiffening agent), cilostazol (phosphodiesterase 3 inhibitor), or vehicle control. The mean change in RBC ATP release from normoxia to hypoxia in control conditions was significantly impaired in older vs. young (∼50% vs. ∼120%; P < 0.05). RBC deformability was also lower in older vs. young as indicated by a higher RBC transit time (RCTT) measured by blood filtrometry (RCTT: 8.541 ± 0.050 vs. 8.234 ± 0.098 a.u., respectively; P < 0.05). Y-27632 improved RBC deformability (RCTT: 8.228 ± 0.083) and ATP release (111.7 ± 17.2%) in older and diamide decreased RBC deformability (RCTT: 8.955 ± 0.114) and ATP release (67.4 ± 11.8%) in young (P < 0.05), abolishing the age group differences (P > 0.05). Cilostazol did not change ATP release in either age group (P > 0.05), and RBC cAMP and ATP release to pharmacological Gi protein activation was similar in both groups (P > 0.05). We conclude that decreased RBC deformability is a primary contributor to age-related impairments in RBC ATP release, which may have implications for impaired vascular control with advancing age.
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Affiliation(s)
- Matthew L Racine
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, 80523, USA
| | - Frank A Dinenno
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, 80523, USA.,Cardiovascular Research Center, Colorado State University, Fort Collins, CO, 80523, USA
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15
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Groen MB, Knudsen TA, Finsen SH, Pedersen BK, Hellsten Y, Mortensen SP. Reduced skeletal-muscle perfusion and impaired ATP release during hypoxia and exercise in individuals with type 2 diabetes. Diabetologia 2019; 62:485-493. [PMID: 30607464 DOI: 10.1007/s00125-018-4790-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 11/08/2018] [Indexed: 12/13/2022]
Abstract
AIMS/HYPOTHESIS Plasma ATP is a potent vasodilator and is thought to play a role in the local regulation of blood flow. Type 2 diabetes is associated with reduced tissue perfusion. We aimed to examine whether individuals with type 2 diabetes have reduced plasma ATP concentrations compared with healthy control participants (case-control design). METHODS We measured femoral arterial and venous plasma ATP levels with the intravascular microdialysis technique during normoxia, hypoxia and one-legged knee-extensor exercise (10 W and 30 W) in nine participants with type 2 diabetes and eight control participants. In addition, we infused acetylcholine (ACh), sodium nitroprusside (SNP) and ATP into the femoral artery to assess vascular function and ATP signalling. RESULTS Individuals with type 2 diabetes had a lower leg blood flow (LBF; 2.9 ± 0.1 l/min) compared with the control participants (3.2 ± 0.1 l/min) during exercise (p < 0.05), in parallel with lower venous plasma ATP concentration (205 ± 35 vs 431 ± 72 nmol/l; p < 0.05). During systemic hypoxia, LBF increased from 0.35 ± 0.04 to 0.54 ± 0.06 l/min in control individuals, whereas it did not increase (0.25 ± 0.04 vs 0.31 ± 0.03 l/min) in the those with type 2 diabetes and was lower than in the control individuals (p < 0.05). Hypoxia increased venous plasma ATP levels in both groups (p < 0.05), but the increase was higher in control individuals (90 ± 26 nmol/l) compared to those with type 2 diabetes (18 ± 5 nmol/l). LBF and vascular conductance were lower during ATP (0.15 and 0.4 μmol min-1 [kg leg mass]-1) and ACh (100 μg min-1 [kg leg mass]-1) infusion in individuals with type 2 diabetes compared with the control participants (p < 0.05), whereas there was no difference during SNP infusion. CONCLUSIONS/INTERPRETATION These findings demonstrate that individuals with type 2 diabetes have lower plasma ATP concentrations during exercise and hypoxia compared with control individuals, and this occurs in parallel with lower blood flow. Moreover, individuals with type 2 diabetes have a reduced vasodilatory response to infused ATP. These impairments in the ATP system are both likely to contribute to the reduced tissue perfusion associated with type 2 diabetes. TRIAL REGISTRATION ClinicalTrials.gov NCT02001766.
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Affiliation(s)
- Martin B Groen
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Winslowparken 21 3, 5000, Odense, Denmark
| | - Trine A Knudsen
- Centre of Inflammation and Metabolism and the Centre for Physical Activity Research, University of Copenhagen, Rigshospitalet, Copenhagen, Denmark
| | - Stine H Finsen
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Winslowparken 21 3, 5000, Odense, Denmark
| | - Bente K Pedersen
- Centre of Inflammation and Metabolism and the Centre for Physical Activity Research, University of Copenhagen, Rigshospitalet, Copenhagen, Denmark
| | - Ylva Hellsten
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Stefan P Mortensen
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Winslowparken 21 3, 5000, Odense, Denmark.
- Centre of Inflammation and Metabolism and the Centre for Physical Activity Research, University of Copenhagen, Rigshospitalet, Copenhagen, Denmark.
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16
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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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17
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Fujii N, Nishiyasu T, Sigal RJ, Boulay P, McGarr GW, Kenny GP. Aging attenuates adenosine triphosphate-induced, but not muscarinic and nicotinic, cutaneous vasodilation in men. Microcirculation 2018; 25:e12462. [PMID: 29846993 DOI: 10.1111/micc.12462] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Revised: 05/13/2018] [Accepted: 05/28/2018] [Indexed: 12/22/2022]
Abstract
OBJECTIVE We evaluated the hypothesis that aging attenuates muscarinic, nicotinic, and ATP-related cutaneous vasodilation. METHODS In 11 young (24 ± 4 years) and 11 older males (61 ± 8 years), CVC was assessed at 3 forearm skin sites that were infused with either: (i) methacholine (muscarinic receptor agonist, 5 doses: 0.0125, 0.25, 5, 100, 2000 mmol/L), (ii) nicotine (nicotinic receptor agonist, 5 doses: 1.2, 3.6, 11, 33, 100 mmol/L), or (iii) ATP (purinergic receptor agonist, 5 doses: 0.03, 0.3, 3, 30, 300 mmol/L). Each agonist was administered for 25 minutes per dose. RESULTS We showed that CVC at all doses of methacholine did not differ between groups. Similarly, no between-group differences in CVC were observed during nicotine administration at all doses administered. By contrast, while no differences in CVC were measured during the administration of ATP at low (0.03 and 0.3 mmol/L) or high (300 mmol/L) concentrations, CVC was reduced in the older relative to the young males at moderate concentrations of ATP (3 mmol/L: 23 ± 6 vs 40 ± 13%max, 30 mmol/L: 62 ± 11 vs 83 ± 8%max, both P ≤ .05). CONCLUSIONS We show that aging attenuates ATP-induced, but not muscarinic or nicotinic, cutaneous vasodilation in men.
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Affiliation(s)
- Naoto Fujii
- Human and Environmental Physiology Research Unit, University of Ottawa, Ottawa, ON, Canada.,Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba, Japan
| | - Takeshi Nishiyasu
- Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba, Japan
| | - Ronald J Sigal
- Human and Environmental Physiology Research Unit, University of Ottawa, Ottawa, ON, Canada.,Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Pierre Boulay
- Faculty of Physical Activity Sciences, University of Sherbrooke, Sherbrooke, QC, Canada
| | - Gregory W McGarr
- Human and Environmental Physiology Research Unit, University of Ottawa, Ottawa, ON, Canada
| | - Glen P Kenny
- Human and Environmental Physiology Research Unit, University of Ottawa, Ottawa, ON, Canada.,Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
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18
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Bentley RF, Walsh JJ, Drouin PJ, Velickovic A, Kitner SJ, Fenuta AM, Tschakovsky ME. Absence of compensatory vasodilation with perfusion pressure challenge in exercise: evidence for and implications of the noncompensator phenotype. J Appl Physiol (1985) 2018; 124:374-387. [PMID: 28706000 DOI: 10.1152/japplphysiol.00952.2016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Compromising oxygen delivery (O2D) during exercise requires compensatory vasodilatory and/or pressor responses to protect O2D:demand matching. The purpose of the study was to determine whether compensatory vasodilation is absent in some healthy young individuals in the face of a sudden reduction in exercising forearm perfusion pressure and whether this affects the exercise pressor response. Twenty-one healthy young men (21.6 ± 2.0 yr) completed rhythmic forearm exercise at a work rate equivalent to 70% of their own maximal exercise vasodilation. During steady-state exercise, the exercising arm was rapidly adjusted from below to above heart level, resulting in a reduction in forearm perfusion pressure of -30.7 ± 0.9 mmHg. Forearm blood flow (ml/min; brachial artery Doppler and echo ultrasound), mean arterial blood pressure (mmHg; finger photoplethysmography), and exercising forearm venous effluent (antecubital vein catheter) measurements revealed distinct compensatory vasodilatory differences. Thirteen individuals responded with compensatory vasodilation (509 ± 128 vs. 632 ± 136 ml·min-1·100 mmHg-1; P < 0.001), while eight individuals did not (663 ± 165 vs. 667 ± 167 ml·min-1·100 mmHg-1; P = 0.6). Compensatory pressor responses between groups were not different (5.5 ± 5.5 and 9.7 ± 9.5 mmHg; P = 0.2). Forearm blood flow, O2D, and oxygen consumption were all protected in compensators (all P > 0.05) but not in noncompensators, who therefore suffered compromises to exercise performance (6 ± 14 vs. -36 ± 29 N; P = 0.004). Phenotypic differences were not explained by potassium or nitric oxide bioavailability. In conclusion, both compensator and noncompensator vasodilator phenotype responses to a sudden compromise to exercising muscle blood flow are evident. Interindividual differences in the mechanisms governing O2D:demand matching should be considered as factors influencing exercise tolerance. NEW & NOTEWORTHY In healthy young individuals, compromising submaximally exercising muscle perfusion appears to evoke compensatory vasodilation to defend oxygen delivery. Here we report the absence of compensatory vasodilation in 8 of 21 such individuals, despite their vasodilatory capacity and increases in perfusion with increasing exercise intensity being indistinguishable from compensators. The absence of compensation impaired exercise tolerance. These findings suggest that interindividual differences in oxygen delivery:demand matching efficacy affect exercise tolerance and depend on the nature of a delivery:demand matching challenge.
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Affiliation(s)
- Robert F Bentley
- 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
| | - Patrick J Drouin
- School of Kinesiology and Health Studies, Queen's University , Kingston, Ontario , Canada
| | - Aleksandra Velickovic
- School of Kinesiology and Health Studies, Queen's University , Kingston, Ontario , Canada
| | - Sarah J Kitner
- School of Kinesiology and Health Studies, Queen's University , Kingston, Ontario , Canada
| | - Alyssa M Fenuta
- 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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19
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Evidence of a metabolic reserve in the skeletal muscle of elderly people. Aging (Albany NY) 2017; 9:52-67. [PMID: 27824313 PMCID: PMC5310656 DOI: 10.18632/aging.101079] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 10/20/2016] [Indexed: 11/25/2022]
Abstract
The purpose of the present study was to determine whether mitochondrial function is limited by O2 availability or the intrinsic capacity of mitochondria to synthesize ATP in elderly individuals. To this aim, we examined, in comparison to free-flow conditions (FF), the effect of superimposing reactive hyperemia (RH), induced by a period of brief ischemia during the last min of exercise, on O2 availability and mitochondrial function in the calf muscle. 12 healthy, untrained, elderly subjects performed dynamic plantar flexion exercise and phosphorus magnetic resonance spectroscopy (31P-MRS), near-infrared spectroscopy (NIRS), and Doppler ultrasound were used to assess muscle metabolism and peripheral hemodynamics. Limb blood flow [area under the curve (AUC), FF: 1.5±0.5L; RH: 3.2±1.1L, P<0.01] and convective O2 delivery (AUC, FF: 0.30±0.13L; RH: 0.64±0.29L, P<0.01) were significantly increased in RH in comparison to FF. RH was also associated with significantly higher capillary blood flow (P<0.05) and this resulted in a 33% increase in estimated peak mitochondrial ATP synthesis rate (FF: 24±11 mM.min−1; RH: 31±7 mM.min−1, P<0.05). These results document a hemodynamic reserve in the contracting calf muscle of the elderly accessible by superimposing reactive hyperemia. Furthermore, this increase in O2 availability enhanced mitochondrial function thus indicating a skeletal muscle metabolic reserve despite advancing age and low level of physical activity.
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Hong KS, Kim K. Skeletal muscle contraction-induced vasodilation in the microcirculation. J Exerc Rehabil 2017; 13:502-507. [PMID: 29114523 PMCID: PMC5667595 DOI: 10.12965/jer.1735114.557] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 10/08/2017] [Indexed: 11/22/2022] Open
Abstract
Maximal whole body exercise leads skeletal muscle blood flow to markedly increase to match metabolic demands, a phenomenon termed exercise hyperaemia that is accomplished by increasing vasodilation. However, local vasodilatory mechanisms in response to skeletal muscle contraction remain uncertain. This review highlights metabolic vasodilators released from contracting skeletal muscle, endothelium, or blood cells. As a considerable skeletal muscle vasodilation potentially results in hypotension, sympathetic nerve activity needs to be augmented to elevate cardiac output and blood pressure during dynamic exercise. However, since the enhanced sympathetic vasoconstriction restrains skeletal muscle blood flow, intramuscular arteries have an indispensable ability to blunt sympathetic activity for exercise hyperaemia. In addition, we discuss that mechanical compression of the intramuscular vasculature contributes to causing the initial phase of increasing vasodilation following a single muscle contraction. We have also chosen to focus on conducted (or ascending) electrical signals that evoke vasodilation of proximal feed arteries to elevate blood flow in the microcirculation of skeletal muscle. Endothelial hyperpolarization originating within distal arterioles ascends into the proximal feed arteries, thereby increasing total blood flow in contracting skeletal muscle. This brief review summarizes molecular mechanisms underlying the regulation of skeletal muscle blood flow to a single or sustained muscle contraction.
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Affiliation(s)
- Kwang-Seok Hong
- Robert M. Berne Cardiovascular Research Center, University of Virginia-School of Medicine, Charlottesville, VA, USA
| | - Kijeong Kim
- School of Exercise & Sport Science, College of Natural Sciences, University of Ulsan, Ulsan, Korea
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21
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Iepsen UW, Munch GW, Ryrsø CK, Secher NH, Lange P, Thaning P, Pedersen BK, Mortensen SP. Muscle α-adrenergic responsiveness during exercise and ATP-induced vasodilation in chronic obstructive pulmonary disease patients. Am J Physiol Heart Circ Physiol 2017; 314:H180-H187. [PMID: 29030339 DOI: 10.1152/ajpheart.00398.2017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Sympathetic vasoconstriction is blunted in exercising muscle (functional sympatholysis) but becomes attenuated with age. We tested the hypothesis that functional sympatholysis is further impaired in chronic obstructive pulmonary disease (COPD) patients. We determined leg blood flow and calculated leg vascular conductance (LVC) during 1) femoral-arterial Tyramine infusion (evokes endogenous norepinephrine release, 1 µmol·min-1·kg leg mass-1), 2) one-legged knee extensor exercise with and without Tyramine infusion [10 W and 20% of maximal workload (WLmax)], 3) ATP (0.05 µmol·min-1·kg leg mass-1) and Tyramine infusion, and 4) incremental ATP infusions (0.05, 0.3, and 3.0 µmol·min-1·kg leg mass-1). We included 10 patients with moderate to severe COPD and 8 age-matched healthy control subjects. Overall, leg blood flow and LVC were lower in COPD patients during exercise ( P < 0.05). Tyramine reduced LVC in both groups at 10-W exercise (COPD: -3 ± 1 ml·min-1·mmHg-1 and controls: -3 ± 1 ml·min-1·mmHg-1, P < 0.05) and 20% WLmax (COPD: -4 ± 1 ml·min-1·mmHg-1 and controls: -3 ± 1 ml·min-1·mmHg-1, P < 0.05) with no difference between groups. Incremental ATP infusions induced dose-dependent vasodilation with no difference between groups, and, in addition, the vasoconstrictor response to Tyramine infused together with ATP was not different between groups (COPD: -0.03 ± 0.01 l·min-1·kg leg mass-1 vs. CONTROLS -0.04 ± 0.01 l·min-1·kg leg mass-1, P > 0.05). Compared with age-matched healthy control subjects, the vasodilatory response to ATP is intact in COPD patients and their ability to blunt sympathetic vasoconstriction (functional sympatholysis) as evaluated by intra-arterial Tyramine during exercise or ATP infusion is maintained. NEW & NOTEWORTHY The ability to blunt sympathetic vasoconstriction in exercising muscle and ATP-induced dilation in chronic obstructive pulmonary disease patients remains unexplored. Chronic obstructive pulmonary disease patients demonstrated similar sympathetic vasoconstriction in response to intra-arterial Tyramine during exercise and ATP-induced vasodilation compared with age-matched healthy control subjects.
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Affiliation(s)
- U W Iepsen
- Centre of Inflammation and Metabolism and Centre for Physical Activity Research, University of Copenhagen, Rigshospitalet, Copenhagen , Denmark
| | - G W Munch
- Centre of Inflammation and Metabolism and Centre for Physical Activity Research, University of Copenhagen, Rigshospitalet, Copenhagen , Denmark
| | - C K Ryrsø
- Centre of Inflammation and Metabolism and Centre for Physical Activity Research, University of Copenhagen, Rigshospitalet, Copenhagen , Denmark
| | - N H Secher
- Department of Anesthesiology, The Copenhagen Muscle Research Centre, University of Copenhagen, Rigshospitalet, Copenhagen , Denmark
| | - P Lange
- Centre of Inflammation and Metabolism and Centre for Physical Activity Research, University of Copenhagen, Rigshospitalet, Copenhagen , Denmark.,Medical Department O, Respiratory Section, Herlev and Gentofte Hospital, Copenhagen , Denmark.,Department of Public Health, Section of Social Medicine, University of Copenhagen , Copenhagen , Denmark
| | - P Thaning
- Centre of Inflammation and Metabolism and Centre for Physical Activity Research, University of Copenhagen, Rigshospitalet, Copenhagen , Denmark.,Medical Department O, Respiratory Section, Herlev and Gentofte Hospital, Copenhagen , Denmark
| | - B K Pedersen
- Centre of Inflammation and Metabolism and Centre for Physical Activity Research, University of Copenhagen, Rigshospitalet, Copenhagen , Denmark
| | - S P Mortensen
- Centre of Inflammation and Metabolism and Centre for Physical Activity Research, University of Copenhagen, Rigshospitalet, Copenhagen , Denmark.,Department of Cardiovascular and Renal Research, University of Southern Denmark, Denmark
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Shinbara H, Nagaoka S, Izutani Y, Okubo M, Kimura K, Mizunuma K, Sumiya E. Contribution of Adenosine to the Increase in Skeletal Muscle Blood Flow Caused by Manual Acupuncture in Rats. Acupunct Med 2017; 35:284-288. [DOI: 10.1136/acupmed-2016-011152] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/23/2016] [Indexed: 01/17/2023]
Abstract
Background and aim Adenosine is believed to play an important role in local acupuncture analgesia. The aim of this study was to investigate the contribution of adenosine to the increase in skeletal muscle blood flow (MBF) caused by manual acupuncture (MA). Methods Thirty-two male Sprague-Dawley rats (310–360 g) were anaesthetised and divided into four equal groups (n=8 each): Saline, Saline+MA, Theophylline, and Theophylline+MA. In the two MA groups, the sparrow-pecking MA technique was applied at 30 repetitions per min for 1 min to a depth of 15–18 mm using a stainless steel acupuncture needle (0.20×40 mm). The stimulus point was located on the right tibialis anterior (TA) muscle 7–8 mm below the knee. Animals in the two theophylline groups were intra-arterially injected with 8-(p-sulphophenyl) theophylline, a non-selective adenosine receptor antagonist, at a dose of 30 mg/kg before MA. Animals in the two saline groups received control saline. Fluorescent microspheres (15 µm in diameter, yellow-green fluorescent) were used for MBF measurement in all four groups. Results MA of the TA muscle significantly increased MBF (Saline+MA vs Saline: p=0.001; Saline+MA vs Theophylline: p=0.008). Pre-treatment with theophylline appeared to inhibit this increase (Theophylline vs Theophylline+MA; p=1.000). MBF in the Theophylline+MA group was 43% lower than in the Saline+MA group, although this was not significantly different (p=0.104). Conclusions The results suggest that adenosine leads to an increase in MBF caused by MA. Adenosine may play a role in acupuncture analgesia by washing out algesic substances. Further studies are needed in order to elucidate the precise mechanism.
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Affiliation(s)
- Hisashi Shinbara
- Department of Basic Acupuncture and Moxibustion, Meiji University of Integrative Medicine, Nantan-shi, Kyoto, Japan
| | - Satomi Nagaoka
- Department of Basic Acupuncture and Moxibustion, Meiji University of Integrative Medicine, Nantan-shi, Kyoto, Japan
| | - Yasuyuki Izutani
- Department of Basic Acupuncture and Moxibustion, Meiji University of Integrative Medicine, Nantan-shi, Kyoto, Japan
| | - Masamichi Okubo
- Department of Anatomy and Neuroscience, Hyogo College of Medicine, Nishinomiya-shi, Hyogo, Japan
| | - Keisaku Kimura
- Department of Health Promoting and Geriatric Acupuncture and Moxibustion, Meiji University of Integrative Medicine, Nantan-shi, Kyoto, Japan
| | - Kunio Mizunuma
- Department of Health Promoting and Geriatric Acupuncture and Moxibustion, Meiji University of Integrative Medicine, Nantan-shi, Kyoto, Japan
| | - Eiji Sumiya
- Department of Basic Acupuncture and Moxibustion, Meiji University of Integrative Medicine, Nantan-shi, Kyoto, Japan
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Bentley RF, Walsh JJ, Drouin PJ, Velickovic A, Kitner SJ, Fenuta AM, Tschakovsky ME. Dietary nitrate restores compensatory vasodilation and exercise capacity in response to a compromise in oxygen delivery in the noncompensator phenotype. J Appl Physiol (1985) 2017; 123:594-605. [PMID: 28596274 DOI: 10.1152/japplphysiol.00953.2016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 06/07/2017] [Accepted: 06/07/2017] [Indexed: 12/16/2022] Open
Abstract
Recently, dietary nitrate supplementation has been shown to improve exercise capacity in healthy individuals through a potential nitrate-nitrite-nitric oxide pathway. Nitric oxide has been shown to play an important role in compensatory vasodilation during exercise under hypoperfusion. Previously, we established that certain individuals lack a vasodilation response when perfusion pressure reductions compromise exercising muscle blood flow. Whether this lack of compensatory vasodilation in healthy, young individuals can be restored with dietary nitrate supplementation is unknown. Six healthy (21 ± 2 yr), recreationally active men completed a rhythmic forearm exercise. During steady-state exercise, the exercising arm was rapidly transitioned from an uncompromised (below heart) to a compromised (above heart) position, resulting in a reduction in local pressure of -31 ± 1 mmHg. Exercise was completed following 5 days of nitrate-rich (70 ml, 0.4 g nitrate) and nitrate-depleted (70 ml, ~0 g nitrate) beetroot juice consumption. Forearm blood flow (in milliliters per minute; brachial artery Doppler and echo ultrasound), mean arterial blood pressure (in millimeters of mercury; finger photoplethysmography), exercising forearm venous effluent (ante-cubital vein catheter), and plasma nitrite concentrations (chemiluminescence) revealed two distinct vasodilatory responses: nitrate supplementation increased (plasma nitrite) compared with placebo (245 ± 60 vs. 39 ± 9 nmol/l; P < 0.001), and compensatory vasodilation was present following nitrate supplementation (568 ± 117 vs. 714 ± 139 ml ⋅ min-1 ⋅ 100 mmHg-1; P = 0.005) but not in placebo (687 ± 166 vs. 697 ± 171 min-1 ⋅ 100 mmHg-1; P = 0.42). As such, peak exercise capacity was reduced to a lesser degree (-4 ± 39 vs. -39 ± 27 N; P = 0.01). In conclusion, dietary nitrate supplementation during a perfusion pressure challenge is an effective means of restoring exercise capacity and enabling compensatory vasodilation.NEW & NOTEWORTHY Previously, we identified young, healthy persons who suffer compromised exercise tolerance when exercising muscle perfusion pressure is reduced as a result of a lack of compensatory vasodilation. The ability of nitrate supplementation to restore compensatory vasodilation in such noncompensators is unknown. We demonstrated that beetroot juice supplementation led to compensatory vasodilation and restored perfusion and exercise capacity. Elevated plasma nitrite is an effective intervention for correcting the absence of compensatory vasodilation in the noncompensator phenotype.
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Affiliation(s)
- Robert F Bentley
- 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
| | - Patrick J Drouin
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
| | - Aleksandra Velickovic
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
| | - Sarah J Kitner
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
| | - Alyssa M Fenuta
- 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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Shepherd JRA, Joyner MJ, Dinenno FA, Curry TB, Ranadive SM. Prolonged adenosine triphosphate infusion and exercise hyperemia in humans. J Appl Physiol (1985) 2016; 121:629-35. [PMID: 27445304 DOI: 10.1152/japplphysiol.01034.2015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 07/15/2016] [Indexed: 11/22/2022] Open
Abstract
In humans, intra-arterial ATP infusion in limbs mimics many features of exercise hyperemia. However, it remains unknown whether ATP can evoke the prolonged vasodilation seen during exercise. Therefore, we addressed two questions during a continuous 3-h brachial artery infusion of ATP [20 μg·100 ml forearm volume (FAV)(-1)·min(-1)]: 1) would skeletal muscle blood flow remain robust or wane over time (tachyphylaxis); and 2) would the hyperemic response to moderate-intensity exercise performed during the ATP administration be blunted compared with that during control (saline) infusion. Nine participants (25 ± 1 yr) performed one trial consisting of seven bouts of rhythmic handgrip exercise (20 contractions/min at 20% of maximum), two bouts during saline (control), and five bouts during 180 min of continuous ATP infusion. Five minutes of ATP infusion resulted in a 710% increase in forearm vascular conductance (FVC) from control (4.8 ± 0.77 vs. 35.0 ± 5.7 ml·min(-1)·100 mmHg(-1)·dl FAV(-1), P < 0.05). Contrary to our expectations, FVC did not wane over time with values of 35.0 ± 5.7 and 36.0 ± 7.7 ml·min(-1)·100 mmHg(-1)·dl FAV(-1) (P > 0.05), seen prior to the exercise bouts at 5 vs. 150 min, respectively. During superimposed exercise, FVC increased from 35.0 ± 5.7 to 49.6 ± 5.4 ml·min(-1)·100 mmHg(-1)·dl FAV(-1) at 5 min and 36.0 ± 7.7 to 54.5 ± 5.0 at 150 min (P < 0.05). Our findings demonstrate ATP vasodilation is prolonged over time without tachyphylaxis; however, exercise hyperemia responses remain intact. Our results challenge the metabolic theory of exercise hyperemia, suggesting a disconnect between matching of blood flow and metabolic demand.
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Affiliation(s)
- John R A Shepherd
- Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota; and
| | - Michael J Joyner
- Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota; and
| | - Frank A Dinenno
- Department of Health and Exercise Science, and Center for Cardiovascular Research, Colorado State University, Fort Collins, Colorado
| | - Timothy B Curry
- Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota; and
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Hearon CM, Dinenno FA. Regulation of skeletal muscle blood flow during exercise in ageing humans. J Physiol 2015; 594:2261-73. [PMID: 26332887 DOI: 10.1113/jp270593] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 08/13/2015] [Indexed: 12/12/2022] Open
Abstract
The regulation of skeletal muscle blood flow and oxygen delivery to contracting skeletal muscle is complex and involves the mechanical effects of muscle contraction; local metabolic, red blood cell and endothelium-derived substances; and the sympathetic nervous system (SNS). With advancing age in humans, skeletal muscle blood flow is typically reduced during dynamic exercise and this is due to a lower vascular conductance, which could ultimately contribute to age-associated reductions in aerobic exercise capacity, a primary predictor of mortality in both healthy and diseased ageing populations. Recent findings have highlighted the contribution of endothelium-derived substances to blood flow control in contracting muscle of older adults. With advancing age, impaired nitric oxide availability due to scavenging by reactive oxygen species, in conjunction with elevated vasoconstrictor signalling via endothelin-1, reduces the local vasodilatory response to muscle contraction. Additionally, ageing impairs the ability of contracting skeletal muscle to blunt sympathetic vasoconstriction (i.e. 'functional sympatholysis'), which is critical for the proper regulation of tissue blood flow distribution and oxygen delivery, and could further reduce skeletal muscle perfusion during high intensity and/or large muscle mass exercise in older adults. We propose that initiation of endothelium-dependent hyperpolarization is the underlying signalling event necessary to properly modulate sympathetic vasoconstriction in contracting muscle, and that age-associated impairments in red blood cell adenosine triphosphate release and stimulation of endothelium-dependent vasodilatation may explain impairments in both local vasodilatation and functional sympatholysis with advancing age 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
| | - 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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Crecelius AR, Kirby BS, Dinenno FA. Intravascular ATP and the regulation of blood flow and oxygen delivery in humans. Exerc Sport Sci Rev 2015; 43:5-13. [PMID: 25390296 DOI: 10.1249/jes.0000000000000031] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Regulation of vascular tone is a complex response that integrates multiple signals that allow for blood flow and oxygen supply to match oxygen demand appropriately. Here, we discuss the potential role of intravascular adenosine triphosphate (ATP) as a primary factor in these responses and put forth the hypothesis that deficient ATP release contributes to impairments in vascular control exhibited in aged and diseased populations.
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Affiliation(s)
- Anne R Crecelius
- 1Department Health and Sport Science, University of Dayton, Dayton, OH; 2Digital Sport Science Laboratory, Nike Inc., Beaverton, OR; and 3Departments of Health and Exercise Science, and 4Biomedical Sciences, Colorado State University, Fort Collins, CO
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Crecelius AR, Kirby BS, Hearon CM, Luckasen GJ, Larson DG, Dinenno FA. Contracting human skeletal muscle maintains the ability to blunt α1 -adrenergic vasoconstriction during KIR channel and Na(+) /K(+) -ATPase inhibition. J Physiol 2015; 593:2735-51. [PMID: 25893955 DOI: 10.1113/jp270461] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 04/15/2015] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS During exercise there is a balance between vasoactive factors that facilitate increases in blood flow and oxygen delivery to the active tissue and the sympathetic nervous system, which acts to limit muscle blood flow for the purpose of blood pressure regulation. Functional sympatholysis describes the ability of contracting skeletal muscle to blunt the stimulus for vasoconstriction, yet the underlying signalling of this response in humans is not well understood. We tested the hypothesis that activation of inwardly rectifying potassium channels and the sodium-potassium ATPase pump, two potential vasodilator pathways within blood vessels, contributes to the ability to blunt α1 -adrenergic vasoconstriction. Our results show preserved blunting of α1 -adrenergic vasconstriction despite blockade of these vasoactive factors. Understanding this complex phenomenon is important as it is impaired in a variety of clinical populations. ABSTRACT Sympathetic vasoconstriction in contracting skeletal muscle is blunted relative to that which occurs in resting tissue; however, the mechanisms underlying this 'functional sympatholysis' remain unclear in humans. We tested the hypothesis that α1 -adrenergic vasoconstriction is augmented during exercise following inhibition of inwardly rectifying potassium (KIR ) channels and Na(+) /K(+) -ATPase (BaCl2 + ouabain). In young healthy humans, we measured forearm blood flow (Doppler ultrasound) and calculated forearm vascular conductance (FVC) at rest, during steady-state stimulus conditions (pre-phenylephrine), and after 2 min of phenylephrine (PE; an α1 -adrenoceptor agonist) infusion via brachial artery catheter in response to two different stimuli: moderate (15% maximal voluntary contraction) rhythmic handgrip exercise or adenosine infusion. In Protocol 1 (n = 11 subjects) a total of six trials were performed in three conditions: control (saline), combined enzymatic inhibition of nitric oxide (NO) and prostaglandin (PG) synthesis (l-NMMA + ketorolac) and combined inhibition of NO, PGs, KIR channels and Na(+) /K(+) -ATPase (l-NMMA + ketorolac + BaCl2 + ouabain). In Protocol 2 (n = 6) a total of four trials were performed in two conditions: control (saline), and combined KIR channel and Na(+) /K(+) -ATPase inhibition. All trials occurred after local β-adrenoceptor blockade (propranolol). PE-mediated vasoconstriction was calculated (%ΔFVC) in each condition. Contrary to our hypothesis, despite attenuated exercise hyperaemia of ∼30%, inhibition of KIR channels and Na(+) /K(+) -ATPase, combined with inhibition of NO and PGs (Protocol 1) or alone (Protocol 2) did not enhance α1 -mediated vasoconstriction during exercise (Protocol 1: -27 ± 3%; P = 0.2 vs. control, P = 0.4 vs. l-NMMA + ketorolac; Protocol 2: -21 ± 7%; P = 0.9 vs. control). Thus, contracting human skeletal muscle maintains the ability to blunt α1 -adrenergic vasoconstriction during combined KIR channel and Na(+) /K(+) -ATPase inhibition.
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Affiliation(s)
- Anne R Crecelius
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, 80523, USA
| | - Brett S Kirby
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, 80523, USA
| | - Christopher M Hearon
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, 80523, USA
| | - Gary J Luckasen
- Medical Centre of the Rockies Foundation, University of Colorado Health, Loveland, CO, 80538, USA
| | - Dennis G Larson
- Medical Centre of the Rockies Foundation, University of Colorado Health, Loveland, CO, 80538, USA
| | - Frank A Dinenno
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, 80523, USA.,Centre for Cardiovascular Research, Colorado State University, Fort Collins, CO, 80523, USA
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Groot HJ, Richardson RS. The skeletal muscle microcirculation: if this is the hippodrome for the chariots of vasoactivity, who is the charioteer? Exp Physiol 2014; 99:78-9. [PMID: 24391113 DOI: 10.1113/expphysiol.2013.076372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Richards JC, Luckasen GJ, Larson DG, Dinenno FA. Role of α-adrenergic vasoconstriction in regulating skeletal muscle blood flow and vascular conductance during forearm exercise in ageing humans. J Physiol 2014; 592:4775-88. [PMID: 25194040 DOI: 10.1113/jphysiol.2014.278358] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
In healthy humans, ageing is typically associated with reduced skeletal muscle blood flow and vascular conductance during exercise. Further, there is a marked increase in resting sympathetic nervous system (SNS) activity with age, yet whether augmented SNS-mediated α-adrenergic vasoconstriction contributes to the age-associated impairment in exercising muscle blood flow and vascular tone in humans is unknown. We tested the hypothesis that SNS-mediated vasoconstriction is greater in older than young adults and limits muscle (forearm) blood flow (FBF) during graded handgrip exercise (5, 15, 25% maximal voluntary contraction (MVC)). FBF was measured (Doppler ultrasound) and forearm vascular conductance (FVC) was calculated in 11 young (21 ± 1 years) and 12 older (62 ± 2 years) adults in control conditions and during combined local α- and β-adrenoreceptor blockade via intra-arterial infusions of phentolamine and propranolol, respectively. Under control conditions, older adults exhibited significantly lower FBF and FVC at 15% MVC exercise (22.6 ± 1.3 vs. 29 ± 3.3 ml min(-1) 100 g forearm fat-free mass (FFM)(-1) and 21.7 ± 1.2 vs. 33.6 ± 4.0 ml min(-1) 100 g FFM(-1) 100 mmHg(-1); P < 0.05) and 25% MVC exercise (37.4 ± 1.4 vs. 46.0 ± 4.9 ml min(-1) 100 g FFM(-1) and 33.7 ± 1.4 vs. 49.0 ± 5.7 ml min(-1) 100 g FFM(-1) 100 mmHg(-1); P < 0.05), whereas there was no age group difference at 5% MVC exercise. Local adrenoreceptor blockade increased FBF and FVC at rest and during exercise in both groups, although the increase in FBF and FVC from rest to steady-state exercise was similar in young and older adults across exercise intensities, and thus the age-associated impairment in FBF and FVC persisted. Our data indicate that during graded intensity handgrip exercise, the reduced FVC and subsequently lower skeletal muscle blood flow in older healthy adults is not due to augmented sympathetic vasoconstriction, but rather due to impairments in local signalling or structural limitations in the peripheral vasculature with advancing age.
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Affiliation(s)
- Jennifer C Richards
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, 80523-1582, USA
| | - Gary J Luckasen
- Medical Center of the Rockies Foundation, Poudre Valley Health System, Loveland, CO, 80538, USA
| | - Dennis G Larson
- Medical Center of the Rockies Foundation, Poudre Valley Health System, Loveland, CO, 80538, USA
| | - Frank A Dinenno
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, 80523-1582, USA Vascular Physiology Research Group, Department of Biomedical Sciences, Colorado State University, Fort Collins, CO, 80523-1582, USA
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Burnstock G, Ralevic V. Purinergic signaling and blood vessels in health and disease. Pharmacol Rev 2013; 66:102-92. [PMID: 24335194 DOI: 10.1124/pr.113.008029] [Citation(s) in RCA: 219] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Purinergic signaling plays important roles in control of vascular tone and remodeling. There is dual control of vascular tone by ATP released as a cotransmitter with noradrenaline from perivascular sympathetic nerves to cause vasoconstriction via P2X1 receptors, whereas ATP released from endothelial cells in response to changes in blood flow (producing shear stress) or hypoxia acts on P2X and P2Y receptors on endothelial cells to produce nitric oxide and endothelium-derived hyperpolarizing factor, which dilates vessels. ATP is also released from sensory-motor nerves during antidromic reflex activity to produce relaxation of some blood vessels. In this review, we stress the differences in neural and endothelial factors in purinergic control of different blood vessels. The long-term (trophic) actions of purine and pyrimidine nucleosides and nucleotides in promoting migration and proliferation of both vascular smooth muscle and endothelial cells via P1 and P2Y receptors during angiogenesis and vessel remodeling during restenosis after angioplasty are described. The pathophysiology of blood vessels and therapeutic potential of purinergic agents in diseases, including hypertension, atherosclerosis, ischemia, thrombosis and stroke, diabetes, and migraine, is discussed.
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Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Centre, University College Medical School, Rowland Hill Street, London NW3 2PF, UK; and Department of Pharmacology, The University of Melbourne, Australia.
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Crecelius AR, Kirby BS, Richards JC, Dinenno FA. Mechanical effects of muscle contraction increase intravascular ATP draining quiescent and active skeletal muscle in humans. J Appl Physiol (1985) 2013; 114:1085-93. [PMID: 23429876 PMCID: PMC3633434 DOI: 10.1152/japplphysiol.01465.2012] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Accepted: 02/13/2013] [Indexed: 11/22/2022] Open
Abstract
Intravascular adenosine triphosphate (ATP) evokes vasodilation and is implicated in the regulation of skeletal muscle blood flow during exercise. Mechanical stresses to erythrocytes and endothelial cells stimulate ATP release in vitro. How mechanical effects of muscle contractions contribute to increased plasma ATP during exercise is largely unexplored. We tested the hypothesis that simulated mechanical effects of muscle contractions increase [ATP](venous) and ATP effluent in vivo, independent of changes in tissue metabolic demand, and further increase plasma ATP when superimposed with mild-intensity exercise. In young healthy adults, we measured forearm blood flow (FBF) (Doppler ultrasound) and plasma [ATP](v) (luciferin-luciferase assay), then calculated forearm ATP effluent (FBF×[ATP](v)) during rhythmic forearm compressions (RFC) via a blood pressure cuff at three graded pressures (50, 100, and 200 mmHg; Protocol 1; n = 10) and during RFC at 100 mmHg, 5% maximal voluntary contraction rhythmic handgrip exercise (RHG), and combined RFC + RHG (Protocol 2; n = 10). [ATP](v) increased from rest with each cuff pressure (range 144-161 vs. 64 ± 13 nmol/l), and ATP effluent was graded with pressure. In Protocol 2, [ATP](v) increased in each condition compared with rest (RFC: 123 ± 33; RHG: 51 ± 9; RFC + RHG: 96 ± 23 vs. Mean Rest: 42 ± 4 nmol/l; P < 0.05), and ATP effluent was greatest with RFC + RHG (RFC: 5.3 ± 1.4; RHG: 5.3 ± 1.1; RFC + RHG: 11.6 ± 2.7 vs. Mean Rest: 1.2 ± 0.1 nmol/min; P < 0.05). We conclude that the mechanical effects of muscle contraction can 1) independently elevate intravascular ATP draining quiescent skeletal muscle without changes in local metabolism and 2) further augment intravascular ATP during mild exercise associated with increases in metabolism and local deoxygenation; therefore, it is likely one stimulus for increasing intravascular ATP during exercise in humans.
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Affiliation(s)
- Anne R Crecelius
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Vascular Physiology Research Group, Department of Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
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