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Bennett S, Tiollier E, Owens DJ, Brocherie F, Louis JB. Implications of Heat Stress-induced Metabolic Alterations for Endurance Training. Int J Sports Med 2024; 45:422-435. [PMID: 38401534 DOI: 10.1055/a-2251-3170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/26/2024]
Abstract
Inducing a heat-acclimated phenotype via repeated heat stress improves exercise capacity and reduces athletes̓ risk of hyperthermia and heat illness. Given the increased number of international sporting events hosted in countries with warmer climates, heat acclimation strategies are increasingly popular among endurance athletes to optimize performance in hot environments. At the tissue level, completing endurance exercise under heat stress may augment endurance training adaptation, including mitochondrial and cardiovascular remodeling due to increased perturbations to cellular homeostasis as a consequence of metabolic and cardiovascular load, and this may improve endurance training adaptation and subsequent performance. This review provides an up-to-date overview of the metabolic impact of heat stress during endurance exercise, including proposed underlying mechanisms of altered substrate utilization. Against this metabolic backdrop, the current literature highlighting the role of heat stress in augmenting training adaptation and subsequent endurance performance will be presented with practical implications and opportunities for future research.
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Affiliation(s)
- Samuel Bennett
- Center for Biological Clocks Research, Texas A&M University, College Station, United States
| | - Eve Tiollier
- Laboratory Sport, Expertise and Performance, Research Department, Institut National du Sport de l'Expertise et de la Performance, Paris, France
| | - Daniel J Owens
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom of Great Britain and Northern Ireland
| | - Franck Brocherie
- Laboratory Sport, Expertise and Performance, Research Department, Institut National du Sport de l'Expertise et de la Performance, Paris, France
| | - Julien B Louis
- Laboratory Sport, Expertise and Performance, Research Department, Institut National du Sport de l'Expertise et de la Performance, Paris, France
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom of Great Britain and Northern Ireland
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2
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Giuriato G, Ives SJ, Tarperi C, Bortolan L, Ruzzante F, Cevese A, Schena F, Venturelli M. Central and peripheral haemodynamics at exercise onset: the role of central command. Eur J Appl Physiol 2024:10.1007/s00421-024-05513-3. [PMID: 38819659 DOI: 10.1007/s00421-024-05513-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 05/20/2024] [Indexed: 06/01/2024]
Abstract
PURPOSE The involvement of central command in central hemodynamic regulation during exercise is relatively well-known, although its contribution to peripheral hemodynamics at the onset of low-intensity contractions is debated. This study sought to examine central and peripheral hemodynamics during electrically-evoked muscle contractions (without central command) and voluntary muscle activity (with central command). METHODS Cyclic quadriceps isometric contractions (1 every second), either electrically-evoked (ES; 200 ms trains composed of 20 square waves) or performed voluntarily (VC), were executed by 10 healthy males (26 ± 3 years). In both trials, matched for force output, peripheral and central hemodynamics were analysed. RESULTS At exercise onset, both ES and VC exhibited equal peaks of femoral blood flow (1276 ± 849 vs. 1117 ± 632 ml/min, p > 0.05) and vascular conductance (15 ± 11 vs. 13 ± 7 ml/min/mmHg, p > 0.05), respectively. Similar peaks of heart rate (86 ± 16 bpm vs. 85 ± 16 bpm), stroke volume (100 ± 20 vs. 99 ± 27 ml), cardiac output (8.2 ± 2.5 vs. 8.5 ± 2.1 L/min), and mean arterial pressure (113 ± 13 vs. 113 ± 3 mmHg), were recorded (all, p > 0.05). After ~ 50 s, all the variables drifted to lower values. Collectively, the hemodynamics showed equal responses. CONCLUSION These results suggest a similar pathway for the initial (first 40 s) increase in central and peripheral hemodynamics. The parallel responses may suggest an initial minimal central command involvement during the onset of low-intensity contractions, likely associated with a neural drive activation delay or threshold.
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Affiliation(s)
- Gaia Giuriato
- Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.
- Surgical, Medical and Dental Department of Morphological Sciences Related to Transplant, Oncology and Regenerative Medicine, University of Modena and Reggio Emilia, Modena, Italy.
| | - Stephen J Ives
- Health and Human Physiological Sciences Department, Skidmore College, Saratoga Springs, NY, USA
| | - Cantor Tarperi
- Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Lorenzo Bortolan
- Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Federico Ruzzante
- Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Antonio Cevese
- Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Federico Schena
- Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Massimo Venturelli
- Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
- Department of Internal Medicine, University of Utah, Salt Lake City, UT, USA
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3
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Amin SN, Asali F, Aolymat I, Abuquteish D, Abu Al Karsaneh O, El Gazzar WB, Shaltout SA, Alabdallat YJ, Elberry DA, Kamar SS, Hosny SA, Mehesen MN, Rashed LA, Farag AM, ShamsEldeen AM. Comparing MitoQ10 and heat therapy: Evaluating mechanisms and therapeutic potential for polycystic ovary syndrome induced by circadian rhythm disruption. Chronobiol Int 2023; 40:1004-1027. [PMID: 37548004 DOI: 10.1080/07420528.2023.2241902] [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: 08/31/2022] [Revised: 06/12/2023] [Accepted: 07/23/2023] [Indexed: 08/08/2023]
Abstract
Environmental factors, such as sleep restriction, contribute to polycystic ovary syndrome (PCOS) by causing hyperinsulinemia, hyperandrogenism, insulin resistance, and oligo- or anovulation. This study aimed to evaluate the effects of circadian rhythm disruption on reproductive and metabolic functions and investigate the potential therapeutic benefits of MitoQ10 and hot tub therapy (HTT). Sixty female rats were divided into six groups: control, MitoQ10, HTT, and three groups with PCOS induced by continuous light exposure(L/L). The reproductive, endocrine, and structural manifestations ofL/L-induced PCOS were confirmed by serum biochemical measurements, ultrasound evaluation of ovarian size, and vaginal smear examination at week 14. Subsequently, the rats were divided into the L/L (untreated), L/L+MitoQ10-treated, andL/L+HTT-treated groups. At the end of week 22, all rats were sacrificed. Treatmentwith MitoQ10 or HTT partially reversed the reproductive, endocrine, and structural features of PCOS, leading to a decreased amplitude of isolated uterine contractions, ovarian cystic changes and size, and endometrial thickness. Furthermore, both interventions improved the elevated serum levels of anti-Mullerian hormone (AMH), kisspeptin, Fibulin-1, A disintegrin and metalloproteinase with thrombospondin motifs 19 (ADAMTS-19), lipid profile, homeostatic model assessment for insulin resistance (HOMA-IR), oxidative stress markers, androgen receptors (AR) and their transcription target genes, FKBP52 immunostaining in ovarian tissues, and uterine estrogen receptor alpha (ER-α) and PRimmunostaining. In conclusion, MitoQ10 supplementation and HTT demonstrated the potential for ameliorating metabolic, reproductive, and structural perturbations associated with PCOS induced by circadian rhythm disruption. These findings suggest a potential therapeutic role for these interventions in managing PCOS in women.
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Affiliation(s)
- Shaimaa Nasr Amin
- Department of Anatomy, Physiology and Biochemistry, Faculty of Medicine, The Hashemite University, P.O. Box 330127, Zarqa 13133, Jordan
- Department of Physiology, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Fida Asali
- Department of Obstetrics and Gynaecology, Faculty of Medicine, The Hashemite University, P.O box 330127, Zarqa 13133, Jordan
| | - Iman Aolymat
- Department of Anatomy, Physiology and Biochemistry, Faculty of Medicine, The Hashemite University, P.O. Box 330127, Zarqa 13133, Jordan
| | - Dua Abuquteish
- Department of Microbiology, Pathology and Forensic Medicine, Faculty of Medicine, The Hashemite University, P.O box 330127, Zarqa 13133, Jordan
- Department of Pathology and Laboratory Medicine, King Hussein Cancer Centre, Amman, Jordan
| | - Ola Abu Al Karsaneh
- Department of Microbiology, Pathology and Forensic Medicine, Faculty of Medicine, The Hashemite University, P.O box 330127, Zarqa 13133, Jordan
| | - Walaa Bayoumie El Gazzar
- Department of Anatomy, Physiology and Biochemistry, Faculty of Medicine, The Hashemite University, P.O. Box 330127, Zarqa 13133, Jordan
- Department of Medical Biochemistry and Molecular Biology, Faculty of Medicine, Benha University, Benha, Egypt
| | - Sherif Ahmed Shaltout
- Department of Pharmacology, Public Health, and Clinical Skills, Faculty of Medicine, The Hashemite University, P.O. Box 330127, Zarqa 13133, Jordan
- Department of Pharmacology, Faculty of Medicine, Benha University, Benha, Egypt
| | | | - Dalia Azmy Elberry
- Department of Physiology, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Samaa Samir Kamar
- Department of Histology, Faculty of Medicine, Cairo University, Cairo, Egypt
- Department of Histology, Armed Forces College of Medicine, Cairo, Egypt
| | - Sara Adel Hosny
- Department of Histology, Faculty of Medicine, Cairo University, Cairo, Egypt
- Department of Histology and Cell Biology, Faculty of Medicine, Nahda University, Beni Suef, Egypt
| | - Marwa Nagi Mehesen
- Department of Medical Pharmacology, Faculty of Medicine, Cairo University, Cairo, Egypt
- Department of Pharmacy Practice and Clinical Pharmacy, Faculty of Pharmacy, Future University in Egypt, Cairo, Egypt
| | - Laila Ahmed Rashed
- Department of Biochemistry, Faculty of Medicine, Cairo University, Cairo, Egypt
| | | | - Asmaa Mohammed ShamsEldeen
- Department of Physiology, Faculty of Medicine, Cairo University, Cairo, Egypt
- Department of Physiology, Faculty of Medicine, October 6 University, Cairo, Egypt
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4
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Hyldahl RD, Hafen PS, Nelson WB, Ahmadi M, Pfeifer B, Mehling J, Gifford JR. Passive muscle heating attenuates the decline in vascular function caused by limb disuse. J Physiol 2021; 599:4581-4596. [PMID: 34487346 DOI: 10.1113/jp281900] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 08/31/2021] [Indexed: 01/16/2023] Open
Abstract
Limb disuse has profound negative consequences on both vascular and skeletal muscle health. The purpose of this investigation was to determine whether repeated application of passive heat, applied to the knee extensor muscles, could mitigate the detrimental effects of limb disuse on vascular function. This was a randomized, single-blinded placebo controlled trial. Twenty-one healthy volunteers (10 women, 11 men) underwent 10 days of unilateral lower limb immobilization and were randomized to receive either a daily 2 h sham (Imm) or heat treatment (Imm+H) using pulsed shortwave diathermy. Vascular function was assessed with Doppler ultrasound of the femoral artery and the passive leg movement technique. Biopsies of the vastus lateralis were also collected before and after the intervention. In Imm, femoral artery diameter (FAD) and PLM-induced hyperaemia (HYP) were reduced by 7.3% and 34.3%, respectively. Changes in both FAD (4% decrease; P = 0.0006) and HYP (7.8% increase; P = 0.003) were significantly attenuated in Imm+H. Vastus lateralis capillary density was not altered in either group. Immobilization significantly decreased expression of vascular endothelial growth factor (P = 0.006) and Akt (P = 0.001), and increased expression of angiopoietin 2 (P = 0.0004) over time, with no differences found between groups. Immobilization also upregulated elements associated with remodelling of the extracellular matrix, including matrix metalloproteinase 2 (P = 0.0046) and fibronectin (P = 0.0163), with no differences found between groups. In conclusion, limb immobilization impairs vascular endothelial function, but daily muscle heating via diathermy is sufficient to counteract this adverse effect. These are the first data to indicate that passive muscle heating mitigates disuse-induced vascular dysfunction. KEY POINTS: Limb disuse can be unavoidable for many of reasons (i.e. injury, bed rest, post-surgery), and can have significant adverse consequences for muscular and vascular health. We tested the hypothesis that declines in vascular function that result from lower limb immobilization could be mitigated by application of passive heat therapy. This report shows that 10 days of limb immobilization significantly decreases resistance artery diameter and vascular function, and that application of passive heat to the knee extensor muscle group each day for 2 h per day is sufficient to attenuate these declines. Additionally, muscle biopsy analyses showed that 10 days of heat therapy does not alter capillary density of the muscle, but upregulates multiple factors indicative of a vascular remodelling response. Our data demonstrate the utility of passive heat as a therapeutic tool to mitigate losses in lower limb vascular function that occur from disuse.
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Affiliation(s)
- Robert D Hyldahl
- Department of Exercise Sciences, Brigham Young University, Provo, UT, USA
| | - Paul S Hafen
- Department of Exercise Sciences, Brigham Young University, Provo, UT, USA
| | - W Bradley Nelson
- Department of Exercise Sciences, Brigham Young University, Provo, UT, USA
| | - Mohadeseh Ahmadi
- Department of Exercise Sciences, Brigham Young University, Provo, UT, USA
| | - Brandon Pfeifer
- Department of Exercise Sciences, Brigham Young University, Provo, UT, USA
| | - Jack Mehling
- Department of Exercise Sciences, Brigham Young University, Provo, UT, USA
| | - Jayson R Gifford
- Department of Exercise Sciences, Brigham Young University, Provo, UT, USA
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5
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Kim K, Ro B, Damen FW, Gramling DP, Lehr TD, Song Q, Goergen CJ, Roseguini BT. Heat therapy improves body composition and muscle function but does not affect capillary or collateral growth in a model of obesity and hindlimb ischemia. J Appl Physiol (1985) 2020; 130:355-368. [PMID: 33180645 DOI: 10.1152/japplphysiol.00535.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Heat therapy (HT) has emerged as a potential adjunctive therapy to alleviate the symptoms of peripheral artery disease (PAD), but the mechanisms underlying the positive effects of this treatment modality remain undefined. Using a model of diet-induced obesity (DIO) and ischemia-induced muscle damage, we tested the hypothesis that HT would alter body composition, promote vascular growth and mitochondrial biogenesis, and improve skeletal muscle function. Male DIO C57Bl/6J mice underwent bilateral ligation of the femoral artery and were randomly allocated to receive HT or a control intervention for 30 min daily over 3 wk. When compared with a group of lean, sham-operated animals, ligated DIO mice exhibited increases in body and fat masses, exercise intolerance, and contractile dysfunction of the isolated soleus (SOL) and extensor digitorum longus (EDL) muscles. Repeated HT averted an increase in body mass induced by high-fat feeding due to reduced fat accrual. Fat mass was ∼25% and 29% lower in the HT group relative to controls after 2 and 3 wk of treatment, respectively. Muscle mass relative to body mass and maximal absolute force of the EDL, but not SOL, were higher in animals exposed to HT. There were no group differences in skeletal muscle capillarization, the expression of angiogenic factors, mitochondrial content, and the diameter of the gracilis arteries. These findings indicate that HT reduces diet-induced fat accumulation and rescues skeletal muscle contractile dysfunction. This practical treatment may prove useful for diabetic and obese PAD patients who are unable to undergo conventional exercise regimens.NEW & NOTEWORTHY The epidemic of obesity-related dyslipidemia and diabetes is a central cause of the increasing burden of peripheral artery disease (PAD), but few accessible therapies exist to mitigate the metabolic and functional abnormalities in these patients. We report that daily exposure to heat therapy (HT) in the form of lower-body immersion in water heated to 39 °C for 3 weeks attenuates fat accumulation and weight gain, and improves muscle strength in obese mice with femoral artery occlusion.
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Affiliation(s)
- Kyoungrae Kim
- Department of Health and Kinesiology, Purdue University, West Lafayette, Indiana
| | - Bohyun Ro
- Department of Health and Kinesiology, Purdue University, West Lafayette, Indiana
| | - Frederick W Damen
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana
| | - Daniel P Gramling
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana
| | - Trevor D Lehr
- Department of Health and Kinesiology, Purdue University, West Lafayette, Indiana
| | - Qifan Song
- Department of Statistics, Purdue University, West Lafayette, Indiana
| | - Craig J Goergen
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana
| | - Bruno T Roseguini
- Department of Health and Kinesiology, Purdue University, West Lafayette, Indiana
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6
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Kim K, Monroe JC, Gavin TP, Roseguini BT. Local Heat Therapy to Accelerate Recovery After Exercise-Induced Muscle Damage. Exerc Sport Sci Rev 2020; 48:163-169. [PMID: 32658042 DOI: 10.1249/jes.0000000000000230] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The prolonged impairment in muscle strength, power, and fatigue resistance after eccentric exercise has been ascribed to a plethora of mechanisms, including delayed muscle refueling and microvascular and mitochondrial dysfunction. This review explores the hypothesis that local heat therapy hastens functional recovery after strenuous eccentric exercise by facilitating glycogen resynthesis, reversing vascular derangements, augmenting mitochondrial function, and stimulating muscle protein synthesis.
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Affiliation(s)
- Kyoungrae Kim
- Department of Health and Kinesiology, Purdue University, West Lafayette, IN
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7
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Kim K, Monroe JC, Gavin TP, Roseguini BT. Skeletal muscle adaptations to heat therapy. J Appl Physiol (1985) 2020; 128:1635-1642. [PMID: 32352340 DOI: 10.1152/japplphysiol.00061.2020] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The therapeutic effects of heat have been harnessed for centuries to treat skeletal muscle disorders and other pathologies. However, the fundamental mechanisms underlying the well-documented clinical benefits associated with heat therapy (HT) remain poorly defined. Foundational studies in cultured skeletal muscle and endothelial cells, as well as in rodents, revealed that episodic exposure to heat stress activates a number of intracellular signaling networks and promotes skeletal muscle remodeling. Renewed interest in the physiology of HT in recent years has provided greater understanding of the signals and molecular players involved in the skeletal muscle adaptations to episodic exposures to HT. It is increasingly clear that heat stress promotes signaling mechanisms involved in angiogenesis, muscle hypertrophy, mitochondrial biogenesis, and glucose metabolism through not only elevations in tissue temperature but also other perturbations, including increased intramyocellular calcium and enhanced energy turnover. The few available translational studies seem to indicate that the earlier observations in rodents also apply to human skeletal muscle. Indeed, recent findings revealed that both local and whole-body HT may promote capillary growth, enhance mitochondrial content and function, improve insulin sensitivity and attenuate disuse-induced muscle wasting. This accumulating body of work implies that HT may be a practical treatment to combat skeletal abnormalities in individuals with chronic disease who are unwilling or cannot participate in traditional exercise-training regimens.
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Affiliation(s)
- Kyoungrae Kim
- Department of Health and Kinesiology, Purdue University, West Lafayette, Indiana
| | - Jacob C Monroe
- Department of Health and Kinesiology, Purdue University, West Lafayette, Indiana
| | - Timothy P Gavin
- Department of Health and Kinesiology, Purdue University, West Lafayette, Indiana
| | - Bruno T Roseguini
- Department of Health and Kinesiology, Purdue University, West Lafayette, Indiana
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8
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Park SH, Kwon OS, Park SY, Weavil JC, Hydren JR, Reese V, Andtbacka RHI, Hyngstrom JR, Richardson RS. Vasodilatory and vascular mitochondrial respiratory function with advancing age: evidence of a free radically mediated link in the human vasculature. Am J Physiol Regul Integr Comp Physiol 2020; 318:R701-R711. [PMID: 32022597 DOI: 10.1152/ajpregu.00268.2019] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recognizing the age-related decline in skeletal muscle feed artery (SMFA) vasodilatory function, this study examined the link between vasodilatory and mitochondrial respiratory function in the human vasculature. Twenty-four SMFAs were harvested from young (35 ± 6 yr, n = 9) and old (71 ± 9 yr, n = 15) subjects. Vasodilation in SMFAs was assessed, by pressure myography, in response to flow-induced shear stress, acetylcholine (ACh), and sodium nitroprusside (SNP) while mitochondrial respiration was measured, by respirometry, in permeabilized SMFAs. Endothelium-dependent vasodilation was significantly attenuated in the old, induced by both flow (young: 92 ± 3, old: 45 ± 4%) and ACh (young: 92 ± 3, old: 54 ± 5%), with no significant difference in endothelium-independent vasodilation. Complex I and I + II state 3 respiration was significantly lower in the old (CI young: 10.1 ± 0.8, old: 7.0 ± 0.4 pmol·s-1·mg-1; CI + II young: 12.3 ± 0.6, old: 7.6 ± 0.4 pmol·s-1·mg-1). The respiratory control ratio (RCR) was also significantly attenuated in the old (young: 2.2 ± 0.1, old: 1.1 ± 0.1). Furthermore, state 3 (CI + II) and 4 respiration, as well as RCR, were significantly correlated (r = 0.49-0.86) with endothelium-dependent, but not endothelium-independent, function. Finally, the direct intervention with mitochondrial-targeted antioxidant (MitoQ) significantly improved endothelium-dependent vasodilation in the old but not in the young. Thus, the age-related decline in vasodilatory function is linked to attenuated vascular mitochondrial respiratory function, likely by augmented free radicals.NEW & NOTEWORTHY In human skeletal muscle feed arteries, the well-recognized age-related fall in endothelium-dependent vasodilatory function is strongly linked to a concomitant fall in vascular mitochondrial respiratory function. The direct intervention with the mitochondrial-targeted antioxidant restored vasodilatory function in the old but not in the young, supporting the concept that exacerbated mitochondrial-derived free radical production is linked to age-related vasodilatory dysfunction. Age-related vasodilatory dysfunction in humans is linked to attenuated vascular mitochondrial respiratory function, likely a consequence of augmented free radical production.
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Affiliation(s)
- Soung Hun Park
- Geriatric Research, Education, and Clinical Center, George E. Whalen Veterans' Affairs Medical Center, Salt Lake City, Utah.,Department of Nutrition and Integrative Physiology, University of Utah Salt Lake City, Utah
| | - Oh Sung Kwon
- Department of Kinesiology, University of Connecticut, Storrs, Connecticut
| | - Song-Young Park
- School of Health and Kinesiology, University of Nebraska, Omaha, Nebraska
| | - Joshua C Weavil
- Geriatric Research, Education, and Clinical Center, George E. Whalen Veterans' Affairs Medical Center, Salt Lake City, Utah.,Division of Geriatrics, Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - Jay R Hydren
- Geriatric Research, Education, and Clinical Center, George E. Whalen Veterans' Affairs Medical Center, Salt Lake City, Utah.,Department of Nutrition and Integrative Physiology, University of Utah Salt Lake City, Utah
| | - Van Reese
- Geriatric Research, Education, and Clinical Center, George E. Whalen Veterans' Affairs Medical Center, Salt Lake City, Utah.,Division of Geriatrics, Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - Robert H I Andtbacka
- Department of Surgery, Huntsman Cancer Hospital, University of Utah, Salt Lake City, Utah
| | - John R Hyngstrom
- Department of Surgery, Huntsman Cancer Hospital, University of Utah, Salt Lake City, Utah
| | - Russell S Richardson
- Geriatric Research, Education, and Clinical Center, George E. Whalen Veterans' Affairs Medical Center, Salt Lake City, Utah.,Department of Nutrition and Integrative Physiology, University of Utah Salt Lake City, Utah.,Division of Geriatrics, Department of Internal Medicine, University of Utah, Salt Lake City, Utah
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9
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Cho JM, Shiu YT, Symons JD, Lee T. Vasoreactivity of the Murine External Jugular Vein and Carotid Artery. J Vasc Res 2020; 57:291-301. [PMID: 32541137 PMCID: PMC7486270 DOI: 10.1159/000508129] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 04/23/2020] [Indexed: 11/19/2022] Open
Abstract
INTRODUCTION Impaired venous reactivity has potential to contribute to clinically significant pathologies such as arteriovenous fistula (AVF) maturation failure. Vascular segments commonly used in murine preclinical models of AVF include the carotid artery and external jugular vein. Detailed descriptions of isometric procedures to evaluate function of murine external jugular vein ex vivo have not been previously published. OBJECTIVE To establish isometric procedures to measure naive murine external jugular vein reactivity ex vivo. METHODS Vasomotor responses of external jugular veins and ipsilateral common carotid arteries from C57BL/6 mice were evaluated using isometric tension procedures. RESULTS External jugular veins developed tension (p < 0.05) to potassium chloride and U-46619, but not to phenylephrine, whereas common carotid arteries responded to all 3 agents (p < 0.05). While maximal responses to acetylcholine (ACh) were similar between the venous and arterial segments, the dose required to achieve this value was lower (p < 0.05) in the artery versus vein. Nitric oxide synthase inhibition attenuated (p < 0.05) but did not abolish ACh-evoked vasorelaxation in both vascular segments, whereas cyclooxygenase blockade had no effect. Endothelium-independent vasorelaxation to sodium nitroprusside was similar in the artery and vein. CONCLUSION Vasorelaxation and vasocontraction can be reliably assessed in the external jugular vein in C57BL/6 mice using isometric procedures.
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Affiliation(s)
- Jae Min Cho
- Department of Nutrition and Integrative Physiology and Molecular Medicine Program, University of Utah, Salt Lake City, Utah, USA.,Division of Endocrinology, Metabolism, and Diabetes, University of Utah, Salt Lake City, Utah, USA
| | - Yan-Ting Shiu
- Veterans Affairs Medical Center, Section of Nephrology, Salt Lake City, Utah, USA.,Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah, Salt Lake City, Utah, USA
| | - J David Symons
- Department of Nutrition and Integrative Physiology and Molecular Medicine Program, University of Utah, Salt Lake City, Utah, USA.,Division of Endocrinology, Metabolism, and Diabetes, University of Utah, Salt Lake City, Utah, USA
| | - Timmy Lee
- Department of Medicine and Division of Nephrology, University of Alabama at Birmingham, Birmingham, Alabama, USA, .,Veterans Affairs Medical Center, Section of Nephrology, Birmingham, Alabama, USA,
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10
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Symons JD, Deeter L, Deeter N, Bonn T, Cho JM, Ferrin P, McCreath L, Diakos NA, Taleb I, Alharethi R, McKellar S, Wever-Pinzon O, Navankasattusas S, Selzman CH, Fang JC, Drakos SG. Effect of Continuous-Flow Left Ventricular Assist Device Support on Coronary Artery Endothelial Function in Ischemic and Nonischemic Cardiomyopathy. Circ Heart Fail 2019; 12:e006085. [DOI: 10.1161/circheartfailure.119.006085] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background:
The coronary vasculature encounters a reduction in pulsatility after implementing durable continuous-flow left ventricular assist device (CF-LVAD) circulatory support. Evidence exists that appropriate pulsatility is required to maintain endothelial cell homeostasis. We hypothesized that coronary artery endothelial function would be impaired after CF-LVAD intervention.
Methods and Results:
Coronary arteries from patients with end-stage heart failure caused by ischemic cardiomyopathy (ICM; n=16) or non-ICM (n=22) cardiomyopathy were isolated from the left ventricular apical core, which was removed for the CF-LVAD implantation. In 11 of these patients, paired coronary arteries were obtained from an adjacent region of myocardium after the CF-LVAD intervention (n=6 ICM, 5 non-ICM). Vascular function was assessed ex vivo using isometric tension procedures in these patients and in 7 nonfailing donor controls. Maximal endothelium-dependent vasorelaxation to BK (bradykinin; 10
−
6
–10
−
10
M) was blunted (
P
<0.05) in arteries from patients with ICM compared with non-ICM and donor controls, whereas responses to sodium nitroprusside (10
−4
–10
−9
M) were similar among the groups. Contrary to our hypothesis, vasorelaxation responses to BK and sodium nitroprusside were similar before and 219±37 days after CF-LVAD support. Of these patients, an exploratory subgroup analysis revealed that BK-induced coronary artery vasorelaxation was greater (
P
<0.05) after (87±6%) versus before (54±14%) CF-LVAD intervention in ICM patients, whereas sodium nitroprusside–evoked responses were similar.
Conclusions:
Coronary artery endothelial function is not impaired by durable CF-LVAD support and in ICM patients appears to be improved. Investigating coronary endothelial function using in vivo approaches in a larger patient population is warranted.
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Affiliation(s)
- J. David Symons
- Department of Nutrition and Integrative Physiology, College of Health, University of Utah, Salt Lake City (J.D.S., L.D., N.D., T.B., J.M.C., S.G.D.)
- Department of Internal Medicine, Division of Endocrinology, Metabolism, and Diabetes (J.D.S.), University of Utah, Salt Lake City
- Molecular Medicine Program (J.D.S., P.F., L.M., N.A.D., I.T., S.N., S.G.D.), University of Utah, Salt Lake City
| | - Lance Deeter
- Department of Nutrition and Integrative Physiology, College of Health, University of Utah, Salt Lake City (J.D.S., L.D., N.D., T.B., J.M.C., S.G.D.)
| | - Nicholas Deeter
- Department of Nutrition and Integrative Physiology, College of Health, University of Utah, Salt Lake City (J.D.S., L.D., N.D., T.B., J.M.C., S.G.D.)
| | - Trevor Bonn
- Department of Nutrition and Integrative Physiology, College of Health, University of Utah, Salt Lake City (J.D.S., L.D., N.D., T.B., J.M.C., S.G.D.)
| | - Jae Min Cho
- Department of Nutrition and Integrative Physiology, College of Health, University of Utah, Salt Lake City (J.D.S., L.D., N.D., T.B., J.M.C., S.G.D.)
| | - Peter Ferrin
- Molecular Medicine Program (J.D.S., P.F., L.M., N.A.D., I.T., S.N., S.G.D.), University of Utah, Salt Lake City
- Nora Eccles Harrison Cardiovascular Research and Training Institute (P.F., L.M., N.A.D., I.T., S.N., C.H.S., S.G.D.), University of Utah, Salt Lake City
| | - Lauren McCreath
- Molecular Medicine Program (J.D.S., P.F., L.M., N.A.D., I.T., S.N., S.G.D.), University of Utah, Salt Lake City
- Nora Eccles Harrison Cardiovascular Research and Training Institute (P.F., L.M., N.A.D., I.T., S.N., C.H.S., S.G.D.), University of Utah, Salt Lake City
| | - Nikolaos A. Diakos
- Molecular Medicine Program (J.D.S., P.F., L.M., N.A.D., I.T., S.N., S.G.D.), University of Utah, Salt Lake City
- Nora Eccles Harrison Cardiovascular Research and Training Institute (P.F., L.M., N.A.D., I.T., S.N., C.H.S., S.G.D.), University of Utah, Salt Lake City
| | - Iosif Taleb
- Molecular Medicine Program (J.D.S., P.F., L.M., N.A.D., I.T., S.N., S.G.D.), University of Utah, Salt Lake City
- Nora Eccles Harrison Cardiovascular Research and Training Institute (P.F., L.M., N.A.D., I.T., S.N., C.H.S., S.G.D.), University of Utah, Salt Lake City
- UTAH Cardiac Transplant Program, Intermountain Medical Center, Salt Lake VA Medical Center (I.T., R.A., S.M., O.W.-P., C.H.S., J.C.F., S.G.D.), University of Utah, Salt Lake City
| | - Rami Alharethi
- UTAH Cardiac Transplant Program, Intermountain Medical Center, Salt Lake VA Medical Center (I.T., R.A., S.M., O.W.-P., C.H.S., J.C.F., S.G.D.), University of Utah, Salt Lake City
| | - Stephen McKellar
- UTAH Cardiac Transplant Program, Intermountain Medical Center, Salt Lake VA Medical Center (I.T., R.A., S.M., O.W.-P., C.H.S., J.C.F., S.G.D.), University of Utah, Salt Lake City
| | - Omar Wever-Pinzon
- UTAH Cardiac Transplant Program, Intermountain Medical Center, Salt Lake VA Medical Center (I.T., R.A., S.M., O.W.-P., C.H.S., J.C.F., S.G.D.), University of Utah, Salt Lake City
| | - Sutip Navankasattusas
- Molecular Medicine Program (J.D.S., P.F., L.M., N.A.D., I.T., S.N., S.G.D.), University of Utah, Salt Lake City
- Nora Eccles Harrison Cardiovascular Research and Training Institute (P.F., L.M., N.A.D., I.T., S.N., C.H.S., S.G.D.), University of Utah, Salt Lake City
| | - Craig H. Selzman
- Nora Eccles Harrison Cardiovascular Research and Training Institute (P.F., L.M., N.A.D., I.T., S.N., C.H.S., S.G.D.), University of Utah, Salt Lake City
- UTAH Cardiac Transplant Program, Intermountain Medical Center, Salt Lake VA Medical Center (I.T., R.A., S.M., O.W.-P., C.H.S., J.C.F., S.G.D.), University of Utah, Salt Lake City
| | - James C. Fang
- UTAH Cardiac Transplant Program, Intermountain Medical Center, Salt Lake VA Medical Center (I.T., R.A., S.M., O.W.-P., C.H.S., J.C.F., S.G.D.), University of Utah, Salt Lake City
| | - Stavros G. Drakos
- Department of Nutrition and Integrative Physiology, College of Health, University of Utah, Salt Lake City (J.D.S., L.D., N.D., T.B., J.M.C., S.G.D.)
- Molecular Medicine Program (J.D.S., P.F., L.M., N.A.D., I.T., S.N., S.G.D.), University of Utah, Salt Lake City
- Nora Eccles Harrison Cardiovascular Research and Training Institute (P.F., L.M., N.A.D., I.T., S.N., C.H.S., S.G.D.), University of Utah, Salt Lake City
- UTAH Cardiac Transplant Program, Intermountain Medical Center, Salt Lake VA Medical Center (I.T., R.A., S.M., O.W.-P., C.H.S., J.C.F., S.G.D.), University of Utah, Salt Lake City
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11
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Park SK, La Salle DT, Cerbie J, Cho JM, Bledsoe A, Nelson A, Morgan DE, Richardson RS, Shiu YT, Boudina S, Trinity JD, Symons JD. Elevated arterial shear rate increases indexes of endothelial cell autophagy and nitric oxide synthase activation in humans. Am J Physiol Heart Circ Physiol 2019; 316:H106-H112. [PMID: 30412436 PMCID: PMC6734082 DOI: 10.1152/ajpheart.00561.2018] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 10/09/2018] [Accepted: 10/22/2018] [Indexed: 11/22/2022]
Abstract
Continuous laminar shear stress increases the process of autophagy, activates endothelial nitric oxide (NO) synthase phosphorylation at serine 1177 (p-eNOSS1177), and generates NO in bovine and human arterial endothelial cells (ECs) compared with static controls. However, the translational relevance of these findings has not been explored. In the current study, primary ECs were collected from the radial artery of 7 men using sterile J-wires before (Pre) and after (Post) 60 min of rhythmic handgrip exercise (HG) performed with the same arm. After ECs were identified by positive costaining for vascular endothelial cadherin and 4',6'-diamidino-2-phenylindole, immunofluorescent antibodies were used to assess indices of autophagy, NO generation, and superoxide anion (O2·-) production. Commercially available primary human arterial ECs were stained and processed in parallel to serve as controls. All end points were evaluated using 75 ECs from each subject. Relative to Pre-HG, HG elevated arterial shear rate ( P < 0.05) ~3-fold, whereas heart rate, arterial pressure, and cardiac output were not altered. Compared with values obtained from ECs Pre-HG, Post-HG ECs displayed increased ( P < 0.05) expression of p-eNOSS1177, NO generation, O2·- production, BECLIN1, microtubule-associated proteins 1A/1B light chain 3B, autophagy-related gene 3, and lysosomal-associated membrane protein 2A and decreased ( P < 0.05) expression (i.e., enhanced degradation) of the adaptor protein p62/sequestosome-1. These novel findings provide evidence that elevated arterial shear rate associated with functional hyperemia initiates autophagy, activates p-eNOSS1177, and increases NO and O2·- generation in primary human ECs. NEW & NOTEWORTHY Previously, our group reported in bovine arterial and human arterial endothelial cells (ECs) that shear stress initiates trafficking of the autophagosome to the lysosome and increases endothelial nitric oxide (NO) synthase phosphorylation at serine 1177, NO generation, and O2·- production. Here, the translational relevance of these findings is documented. Specifically, functional hyperemia induced by rhythmic handgrip exercise elevates arterial shear rate to an extent that increases indices of autophagy, NO generation, and O2·- production in primary arterial ECs collected from healthy men.
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Affiliation(s)
- Seul-Ki Park
- Department of Nutrition and Integrative Physiology, University of Utah , Salt Lake City, Utah
| | - D Taylor La Salle
- Department of Nutrition and Integrative Physiology, University of Utah , Salt Lake City, Utah
- Geriatric Research, Education, and Clinical Center, George E. Wahlen Department of Veterans Affairs Medical Center, and Department of Internal Medicine, University of Utah , Salt Lake City, Utah
| | - James Cerbie
- Department of Nutrition and Integrative Physiology, University of Utah , Salt Lake City, Utah
- Geriatric Research, Education, and Clinical Center, George E. Wahlen Department of Veterans Affairs Medical Center, and Department of Internal Medicine, University of Utah , Salt Lake City, Utah
| | - Jae Min Cho
- Department of Nutrition and Integrative Physiology, University of Utah , Salt Lake City, Utah
| | - Amber Bledsoe
- Department of Anesthesiology, University of Utah , Salt Lake City, Utah
| | - Ashley Nelson
- Geriatric Research, Education, and Clinical Center, George E. Wahlen Department of Veterans Affairs Medical Center, and Department of Internal Medicine, University of Utah , Salt Lake City, Utah
| | - David E Morgan
- Department of Anesthesiology, University of Utah , Salt Lake City, Utah
| | - Russell S Richardson
- Department of Nutrition and Integrative Physiology, University of Utah , Salt Lake City, Utah
- Geriatric Research, Education, and Clinical Center, George E. Wahlen Department of Veterans Affairs Medical Center, and Department of Internal Medicine, University of Utah , Salt Lake City, Utah
- Division of Geriatrics, Department of Internal Medicine, University of Utah , Salt Lake City, Utah
| | - Yan-Ting Shiu
- Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah , Salt Lake City, Utah
| | - Sihem Boudina
- Department of Nutrition and Integrative Physiology, University of Utah , Salt Lake City, Utah
- Division of Endocrinology, Metabolism, and Diabetes, and Molecular Medicine Program, University of Utah School of Medicine , Salt Lake City, Utah
| | - Joel D Trinity
- Department of Nutrition and Integrative Physiology, University of Utah , Salt Lake City, Utah
- Geriatric Research, Education, and Clinical Center, George E. Wahlen Department of Veterans Affairs Medical Center, and Department of Internal Medicine, University of Utah , Salt Lake City, Utah
- Division of Geriatrics, Department of Internal Medicine, University of Utah , Salt Lake City, Utah
| | - J David Symons
- Department of Nutrition and Integrative Physiology, University of Utah , Salt Lake City, Utah
- Division of Endocrinology, Metabolism, and Diabetes, and Molecular Medicine Program, University of Utah School of Medicine , Salt Lake City, Utah
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12
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Hoekstra SP, Bishop NC, Faulkner SH, Bailey SJ, Leicht CA. Acute and chronic effects of hot water immersion on inflammation and metabolism in sedentary, overweight adults. J Appl Physiol (1985) 2018; 125:2008-2018. [DOI: 10.1152/japplphysiol.00407.2018] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Regular exercise-induced acute inflammatory responses are suggested to improve the inflammatory profile and insulin sensitivity. As body temperature elevations partly mediate this response, passive heating might be a viable tool to improve the inflammatory profile. This study investigated the acute and chronic effects of hot water immersion on inflammatory and metabolic markers. Ten sedentary, overweight men [body mass index (BMI): 31.0 ± 4.2 kg/m2, mean ± SD] were immersed in water set at 39°C for 1 h (HWI) or rested for 1 h at ambient temperature (AMB). Venous blood was obtained before the session, immediately postsession, and 2 h postsession for assessment of monocyte intracellular heat shock protein-72 (iHsp72) and plasma concentrations of extracellular Hsp72 (eHsp72), interleukin-6 (IL-6), fasting glucose, insulin, and nitrite. Thereafter, participants underwent a 2-wk intervention period, consisting of 10 hot water immersion sessions (INT). Eight BMI-matched participants (BMI: 30.0 ± 2.5 kg/m2) were included as control (CON). Plasma IL-6 and nitrite concentrations were higher immediately following HWI compared with AMB (IL-6 P < 0.001, HWI: 1.37 ± 0.94 to 2.51 ± 1.49 pg/ml; nitrite P = 0.04, HWI: 271 ± 52 to 391 ± 72 nM), whereas iHsp72 expression was unchanged ( P = 0.57). In contrast to resting iHsp72 expression ( P = 0.59), fasting glucose ( P = 0.04; INT: 4.44 ± 0.93 to 3.98 ± 0.98 mmol/l), insulin ( P = 0.04; INT: 68.1 ± 44.6 to 55.0 ± 29.9 pmol/l), and eHsp72 ( P = 0.03; INT: 17 ± 41% reduction) concentrations were lowered after INT compared with CON. HWI induced an acute inflammatory response and increased nitric oxide bioavailability. The reductions in fasting glucose and insulin concentrations following the chronic intervention suggest that hot water immersion may serve as a tool to improve glucose metabolism. NEW & NOTEWORTHY A single hot water immersion (HWI) session induces an acute increase in plasma interleukin-6 and nitrite concentrations but does not acutely elevate heat shock protein-72 expression in monocytes [intracellular Hsp72 (iHsp72)]. A chronic HWI intervention reduces fasting glucose and insulin concentrations in the absence of changes in resting iHsp72. Therefore, HWI shows potential as a strategy to combat chronic low-grade inflammation and improve glucose metabolism in individuals without the physical capacity to do so using exercise.
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Affiliation(s)
- S. P. Hoekstra
- The Peter Harrison Centre for Disability Sport, Loughborough University, Loughborough, United Kingdom
- The School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, United Kingdom
| | - N. C. Bishop
- The School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, United Kingdom
| | - S. H. Faulkner
- Department of Engineering, Nottingham Trent University, Nottingham, United Kingdom
| | - S. J. Bailey
- The School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, United Kingdom
| | - C. A. Leicht
- The Peter Harrison Centre for Disability Sport, Loughborough University, Loughborough, United Kingdom
- The School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, United Kingdom
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13
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Schlader ZJ, O'Leary MC, Sackett JR, Johnson BD. Face cooling reveals a relative inability to increase cardiac parasympathetic activation during passive heat stress. Exp Physiol 2018; 103:701-713. [PMID: 29450933 DOI: 10.1113/ep086865] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 02/12/2018] [Indexed: 01/31/2023]
Abstract
NEW FINDINGS What is the central question of this study? Does passive heat stress attenuate the increase in cardiac parasympathetic stimulation, vascular resistance and blood pressure evoked by face cooling? What is the main finding and its importance? Passive heat stress attenuates the capacity to increase cardiac parasympathetic activation and impairs the ability to increase vascular resistance during sympathoexcitation, which ultimately results in a relative inability to increase blood pressure. These findings cast doubt on the efficacy of face cooling at augmenting blood pressure during orthostasis while heat stressed. ABSTRACT We tested the hypothesis that passive heat stress attenuates the increase in cardiac parasympathetic stimulation, vascular resistance and blood pressure evoked by face cooling. During normothermia and when intestinal temperature was elevated by 1.0 ± 0.2°C, 10 healthy young adults underwent 3 min of face cooling. Face cooling was accomplished by placing a 2.5 litre bag of ice water (0 ± 0°C) over the cheeks, eyes and forehead. Primary variables included forehead skin temperature, mean arterial pressure and systemic, forearm and cutaneous vascular resistances. Indices of heart rate variability in the time domain provided an index of cardiac parasympathetic activity. The magnitude of reduction in forehead skin temperature during face cooling was slightly greater during normothermia (-17.6 ± 1.9 versus -16.3 ± 3.0°C, P = 0.03). Increases in heart rate variability evoked by face cooling were attenuated during heat stress. Changes in systemic, forearm and cutaneous vascular resistances during face cooling were virtually abolished during heat stress (P < 0.01). However, when forearm and vascular data were reported as conductance, differences between normothermia and heat stress were not apparent (P ≥ 0.62). Nevertheless, the increase in mean arterial pressure was attenuated during heat stress with face cooling (at 3 min: 2 ± 7 mmHg) compared with normothermia (at 3 min: 19 ± 7 mmHg, P < 0.01). These data indicate that passive heat stress attenuates face cooling-evoked increases in cardiac parasympathetic activation, vascular resistance and blood pressure. However, they also indicate that changes in indices of vascular resistance do not always reflect equivalent changes in conductance.
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Affiliation(s)
- Zachary J Schlader
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA
| | - Morgan C O'Leary
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA
| | - James R Sackett
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA
| | - Blair D Johnson
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA
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14
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Mueller PJ, Clifford PS, Crandall CG, Smith SA, Fadel PJ. Integration of Central and Peripheral Regulation of the Circulation during Exercise: Acute and Chronic Adaptations. Compr Physiol 2017; 8:103-151. [DOI: 10.1002/cphy.c160040] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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15
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Gifford JR, Richardson RS. CORP: Ultrasound assessment of vascular function with the passive leg movement technique. J Appl Physiol (1985) 2017; 123:1708-1720. [PMID: 28883048 DOI: 10.1152/japplphysiol.00557.2017] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
As dysfunction of the vascular system is an early, modifiable step in the progression of many cardiovascular diseases, there is demand for methods to monitor the health of the vascular system noninvasively in clinical and research settings. Validated by very good agreement with more technical assessments of vascular function, like intra-arterial drug infusions and flow-mediated dilation, the passive leg movement (PLM) technique has emerged as a powerful, yet relatively simple, test of peripheral vascular function. In the PLM technique, the change in leg blood flow elicited by the passive movement of the leg through a 90° range of motion is quantified with Doppler ultrasound. This relatively easy-to-learn test has proven to be ≤80% dependent on nitric oxide bioavailability and is especially adept at determining peripheral vascular function across the spectrum of cardiovascular health. Indeed, multiple reports have documented that individuals with decreased cardiovascular health such as the elderly and those with heart failure tend to exhibit a substantially blunted PLM-induced hyperemic response (~50 and ~85% reduction, respectively) compared with populations with good cardiovascular health such as young individuals. As specific guidelines have not yet been put forth, the purpose of this Cores of Reproducibility in Physiology (CORP) article is to provide a comprehensive reference for the assessment and interpretation of vascular function with PLM with the aim to increase reproducibility and consistency among studies and facilitate the use of PLM as a research tool with clinical relevance.
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Affiliation(s)
- Jayson R Gifford
- Department of Exercise Sciences, Brigham Young University , Provo, Utah.,Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah.,Department of Internal Medicine, University of Utah , Salt Lake City, Utah
| | - Russell S Richardson
- Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah.,Department of Internal Medicine, University of Utah , Salt Lake City, Utah.,Department of Nutrition and Integrative Physiology, University of Utah , Salt Lake City, Utah
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16
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Ives SJ, Park SY, Kwon OS, Gifford JR, Andtbacka RHI, Hyngstrom JR, Richardson RS. TRPV 1 channels in human skeletal muscle feed arteries: implications for vascular function. Exp Physiol 2017; 102:1245-1258. [PMID: 28681979 DOI: 10.1113/ep086223] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Accepted: 06/30/2017] [Indexed: 12/20/2022]
Abstract
NEW FINDINGS What is the central question of this study? We sought to determine whether human skeletal muscle feed arteries (SFMAs) express TRPV1 channels and what role they play in modulating vascular function. What is the main finding and its importance? Human SMFAs do express functional TRPV1 channels that modulate vascular function, specifically opposing α-adrenergic receptor-mediated vasocontraction and potentiating vasorelaxation, in an endothelium-dependent manner, as evidenced by the α1 -receptor-mediated responses. Thus, the vasodilatory role of TRPV1 channels, and their ligand capsaicin, could be a potential therapeutic target for improving vascular function. Additionally, given the 'sympatholytic' effect of TRPV1 activation and known endogenous activators (anandamide, reactive oxygen species, H+ , etc.), TRPV1 channels might contribute to functional sympatholysis during exercise. To examine the role of the transient receptor potential vanilloid type 1 (TRPV1 ) ion channel in the vascular function of human skeletal muscle feed arteries (SMFAs) and whether activation of this heat-sensitive receptor could be involved in modulating vascular function, SMFAs from 16 humans (63 ± 5 years old, range 41-89 years) were studied using wire myography with capsaicin (TRPV1 agonist) and without (control). Specifically, phenylephrine (α1 -adrenergic receptor agonist), dexmedetomidine (α2 -adrenergic receptor agonist), ACh and sodium nitroprusside concentration-response curves were established to assess the role of TRPV1 channels in α-receptor-mediated vasocontraction as well as endothelium-dependent and -independent vasorelaxation, respectively. Compared with control conditions, capsaicin significantly attenuated maximal vasocontraction in response to phenylephrine [control, 52 ± 8% length-tensionmax (LTmax ) and capsaicin, 21 ± 5%LTmax ] and dexmedetomidine (control, 29 ± 12%LTmax and capsaicin, 2 ± 3%LTmax ), while robustly enhancing maximal vasorelaxation with ACh (control, 78 ± 8% vasorelaxation and capsaicin, 108 ± 13% vasorelaxation) and less clearly enhancing the sodium nitroprusside response. Denudation of the endothelium greatly attenuated the maximal ACh-induced vasorelaxation equally in the control and capsaicin conditions (∼17% vasorelaxation) and abolished the attenuating effect of capsaicin on the maximal phenylephrine response (denuded + capsaicin, 61 ± 20%LTmax ). Immunohistochemistry identified a relatively high density of TRPV1 channels in the endothelium compared with the smooth muscle of the SMFAs, but because of the far greater volume of smooth muscle, total TRPV1 protein content was not significantly attenuated by denudation. Thus, SMFAs ubiquitously express functional TRPV1 channels, which alter vascular function, in terms of α1 -receptors, in a predominantly endothelium-dependent manner, conceivably contributing to the functional sympatholysis and unveiling a therapeutic target.
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Affiliation(s)
- Stephen J Ives
- Geriatric Research, Education and Clinical Center, George E. Whalen VA Medical Center, Salt Lake City, UT, USA.,Department of Internal Medicine, Division of Geriatrics, University of Utah, Salt Lake City, UT, USA.,Department of Health and Exercise Sciences, Skidmore College, Saratoga Springs, NY, USA
| | - Song Young Park
- Geriatric Research, Education and Clinical Center, George E. Whalen VA Medical Center, Salt Lake City, UT, USA
| | - Oh Sung Kwon
- Geriatric Research, Education and Clinical Center, George E. Whalen VA Medical Center, Salt Lake City, UT, USA.,Department of Internal Medicine, Division of Geriatrics, University of Utah, Salt Lake City, UT, USA
| | - Jayson R Gifford
- Geriatric Research, Education and Clinical Center, George E. Whalen VA Medical Center, Salt Lake City, UT, USA.,Department of Internal Medicine, Division of Geriatrics, University of Utah, Salt Lake City, UT, USA
| | - Robert H I Andtbacka
- Department of Surgery, Huntsman Cancer Hospital, University of Utah, Salt Lake City, UT, USA
| | - John R Hyngstrom
- Department of Surgery, Huntsman Cancer Hospital, University of Utah, Salt Lake City, UT, USA
| | - Russell S Richardson
- Geriatric Research, Education and Clinical Center, George E. Whalen VA Medical Center, Salt Lake City, UT, USA.,Department of Internal Medicine, Division of Geriatrics, University of Utah, Salt Lake City, UT, USA.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA
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17
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Ives SJ, Lefferts WK, Wharton M, Fehling PC, Smith DL. Exercise-induced heat stress disrupts the shear-dilatory relationship. Exp Physiol 2016; 101:1541-1551. [PMID: 27647442 DOI: 10.1113/ep085828] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 09/16/2016] [Indexed: 01/31/2023]
Abstract
NEW FINDINGS What is the central question of this study? Although heat stress is known to increase cardiovascular strain, no study, to date, had explored the potential impact of exercise-induced heat stress on vascular function. What is the main finding and its importance? We found that acute exercise tended to reduce flow-mediated dilatation (FMD), owing in part to reduced reactive hyperaemia/shear stimulus; thus, when FMD is normalized to shear no postexercise deficit exists. Exercise-induced heat stress increased reactive hyperaemia, shear rate, coupled with a sustained FMD postexercise, suggests that exercise-induced heat stress increases the amount of shear stimulus to elicit a similar response, indicating reduced vascular responsiveness, or reserve, which might increase cardiovascular susceptibility. Heat stress increases cardiovascular strain and is of particular concern in occupations, such as firefighting, in which individuals are required to perform strenuous work while wearing personal protective equipment. Sudden cardiac events are associated with strenuous activity and are the leading cause of duty-related death among firefighters, accounting for ∼50% of duty-related fatalities per year. Understanding the acute effects of exercise-induced heat stress (EIHS) on vascular endothelial function may provide insight into the mechanisms precipitating acute coronary events in firefighters. The purpose of this study, therefore, was to determine the effects of EIHS on vascular endothelial function. Using a balanced crossover design, 12 healthy men performed 100 min of moderate-intensity, intermittent exercise with and without EIHS (personal protective equipment or cooling vest, respectively). Measurements of flow-mediated dilatation (FMD), reactive hyperaemia and shear rate area under the curve (SRAUC ) were performed pre- and postexercise. During EIHS, core temperature was significantly higher (38 ± 0.1 versus 37 ± 0.1°C). Postexercise FMD tended to be suppressed in both conditions, but was not different from pre-exercise. Reactive hyperaemia was reduced after no-EIHS but increased after EIHS. Thus, normalizing FMD to the shear stimulus (FMD/SRAUC ) revealed a significant reduction in FMD after EIHS only (pre-exercise 0.15 ± 0.04 and 0.13 ± 0.02 s-1 versus postexercise, 0.13 ± 0.02 and 0.06 ± 0.02 s-1 , no-EIHS and EIHS, respectively). We conclude that moderate heat stress superimposed on moderate-intensity exercise resulted in reduced vascular endothelial function. This heat stress-induced alteration in the shear-dilatory relationship may relate to the increased risk of acute coronary events associated with activities that combine physical exertion and heat stress (i.e. firefighting).
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Affiliation(s)
- Stephen J Ives
- Health and Exercise Sciences Department, Skidmore College, Saratoga Springs, NY, USA
| | - Wesley K Lefferts
- Health and Exercise Sciences Department, Skidmore College, Saratoga Springs, NY, USA
| | | | - Patricia C Fehling
- Health and Exercise Sciences Department, Skidmore College, Saratoga Springs, NY, USA
| | - Denise L Smith
- Health and Exercise Sciences Department, Skidmore College, Saratoga Springs, NY, USA
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18
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Just TP, DeLorey DS. Exercise training and α1-adrenoreceptor-mediated sympathetic vasoconstriction in resting and contracting skeletal muscle. Physiol Rep 2016; 4:4/3/e12707. [PMID: 26869686 PMCID: PMC4758927 DOI: 10.14814/phy2.12707] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Exercise training (ET) increases sympathetic vasoconstrictor responsiveness and enhances contraction‐mediated inhibition of sympathetic vasoconstriction (i.e., sympatholysis) through a nitric oxide (NO)‐dependent mechanism. Changes in α2‐adrenoreceptor vasoconstriction mediate a portion of these training adaptations, however the contribution of other postsynaptic receptors remains to be determined. Therefore, the purpose of this study was to investigate the effect of ET on α1‐adrenoreceptor‐mediated vasoconstriction in resting and contracting muscle. It was hypothesized that α1‐adrenoreceptor‐mediated sympatholysis would be enhanced following ET. Male Sprague Dawley rats were randomized to sedentary (S; n = 12) or heavy‐intensity treadmill ET (n = 11) groups. Subsequently, rats were anesthetized and instrumented for lumbar sympathetic chain stimulation and measurement of femoral vascular conductance (FVC) at rest and during muscle contraction. The percentage change in FVC in response to sympathetic stimulation was measured in control, α1‐adrenoreceptor blockade (Prazosin; 20 μg, IV), and combined α1 and NO synthase (NOS) blockade (l‐NAME; 5 mg·kg−1IV) conditions. Sympathetic vasoconstrictor responsiveness was increased (P < 0.05) in ET compared to S rats at low, but not high (P > 0.05) stimulation frequencies at rest (S: 2 Hz: −25 ± 4%; 5 Hz: −45 ± 5 %; ET: 2 Hz: −35 ± 7%, 5 Hz: −52 ± 7%), whereas sympathetic vasoconstrictor responsiveness was not different (P > 0.05) between groups during contraction (S: 2 Hz: −11 ± 8%; 5 Hz: −26 ± 11%; ET: 2 Hz: −10 ± 7%, 5 Hz: −27 ± 12%). Prazosin blunted (P < 0.05) vasoconstrictor responsiveness in S and ET rats at rest and during contraction, and abolished group differences in vasoconstrictor responsiveness. Subsequent NOS blockade increased vasoconstrictor responses (P < 0.05) in S at rest and during contraction, whereas in ET vasoconstriction was increased (P < 0.05) in response to sympathetic stimulation at 2 Hz at rest and unchanged (P > 0.05) during contraction. ET enhanced (P < 0.05) sympatholysis, however the training‐mediated improvements in sympatholysis were abolished by α1‐adrenoreceptor blockade. Subsequent NOS inhibition did not alter (P > 0.05) sympatholysis in S or ET rats. In conclusion, ET augmented α1‐adrenoreceptor‐mediated vasoconstriction in resting skeletal muscle and enhanced α1‐adrenoreceptor‐mediated sympatholysis. Furthermore, these data suggest that NO is not required to inhibit α2‐adrenoreceptor‐ and nonadrenoreceptor‐mediated vasoconstriction during exercise.
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Affiliation(s)
- Timothy P Just
- Faculty of Physical Education and Recreation, University of Alberta, Edmonton, AB, Canada
| | - Darren S DeLorey
- Faculty of Physical Education and Recreation, University of Alberta, Edmonton, AB, Canada
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19
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Park SY, Ives SJ, Gifford JR, Andtbacka RHI, Hyngstrom JR, Reese V, Layec G, Bharath LP, Symons JD, Richardson RS. Impact of age on the vasodilatory function of human skeletal muscle feed arteries. Am J Physiol Heart Circ Physiol 2015; 310:H217-25. [PMID: 26589330 DOI: 10.1152/ajpheart.00716.2015] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 11/13/2015] [Indexed: 11/22/2022]
Abstract
Although advancing age is often associated with attenuated skeletal muscle blood flow and skeletal muscle feed arteries (SMFAs) have been recognized to play a regulatory role in the vasculature, little is known about the impact of age on the vasodilatory capacity of human SMFAs. Therefore, endothelium-dependent and -independent vasodilation were assessed in SMFAs (diameter: 544 ± 63 μm) obtained from 24 (equally represented) young (33 ± 2 yr) and old (71 ± 2 yr) subjects in response to three stimuli: 1) flow-induced shear stress, 2) ACh, and 3) sodium nitropusside (SNP). Both assessments of endothelium-dependent vasodilation, flow (young subjects: 68 ± 1% and old subjects: 32 ± 7%) and ACh (young subjects: 92 ± 3% and old subjects: 73 ± 4%), were significantly blunted (P < 0.05) in SMFAs of old compared with young subjects, with no such age-related differences in endothelium-independent vasodilation (SNP). In response to an increase in flow-induced shear stress, vasodilation kinetics (time constant to reach 63% of the amplitude of the response: 55 ± 1 s in young subjects and 92 ± 7 s in old subjects) and endothelial nitric oxide synthase (eNOS) activation (phospho-eNOS(s1177)/total eNOS: 1.0 ± 0.1 in young subjects and 0.2 ± 0.1 in old subjects) were also significantly attenuated in old compared with young subjects (P < 0.05). Furthermore, the vessel superoxide concentration was greater in old subjects (old subjects: 3.9 ± 1.0 area under curve/mg and young subjects: 1.7 ± 0.1 area under the curve/mg, P < 0.05). These findings reveal that the endothelium-dependent vasodilatory capacity, including vasodilation kinetics but not smooth muscle function, of human SMFAs is blunted with age and may be due to free radicals. Given the potential regulatory role of SMFAs in skeletal muscle blood flow, these findings may explain, at least in part, the often observed attenuated perfusion of skeletal muscle with advancing age that may contribute to exercise intolerance in the elderly.
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Affiliation(s)
- Song-Young Park
- Geriatric Research, Education, and Clinical Center, George E. Whalen Veterans Affairs Medical Center, Salt Lake City, Utah; Department of Exercise and Sport Science, University of Utah, Salt Lake City, Utah
| | - Stephen J Ives
- Geriatric Research, Education, and Clinical Center, George E. Whalen Veterans Affairs Medical Center, Salt Lake City, Utah; Health and Exercise Sciences Department, Skidmore College, Saratoga Springs, New York; and
| | - Jayson R Gifford
- Geriatric Research, Education, and Clinical Center, George E. Whalen Veterans Affairs Medical Center, Salt Lake City, Utah; Department of Exercise and Sport Science, University of Utah, Salt Lake City, Utah
| | - Robert H I Andtbacka
- Department of Surgery, Huntsman Cancer Hospital, University of Utah, Salt Lake City, Utah
| | - John R Hyngstrom
- Department of Surgery, Huntsman Cancer Hospital, University of Utah, Salt Lake City, Utah
| | - Van Reese
- Geriatric Research, Education, and Clinical Center, George E. Whalen Veterans Affairs Medical Center, Salt Lake City, Utah; Division of Geriatrics, Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - Gwenael Layec
- Geriatric Research, Education, and Clinical Center, George E. Whalen Veterans Affairs Medical Center, Salt Lake City, Utah; Division of Geriatrics, Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - Leena P Bharath
- Division of Endocrinology, Metabolism, and Diabetes, School of Medicine, University of Utah, Salt Lake City, Utah
| | - John D Symons
- Department of Exercise and Sport Science, University of Utah, Salt Lake City, Utah; Division of Endocrinology, Metabolism, and Diabetes, School of Medicine, University of Utah, Salt Lake City, Utah
| | - Russell S Richardson
- Geriatric Research, Education, and Clinical Center, George E. Whalen Veterans Affairs Medical Center, Salt Lake City, Utah; Division of Geriatrics, Department of Internal Medicine, University of Utah, Salt Lake City, Utah; Department of Exercise and Sport Science, University of Utah, Salt Lake City, Utah;
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20
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Abstract
Heat stress increases human morbidity and mortality compared to normothermic conditions. Many occupations, disease states, as well as stages of life are especially vulnerable to the stress imposed on the cardiovascular system during exposure to hot ambient conditions. This review focuses on the cardiovascular responses to heat stress that are necessary for heat dissipation. To accomplish this regulatory feat requires complex autonomic nervous system control of the heart and various vascular beds. For example, during heat stress cardiac output increases up to twofold, by increases in heart rate and an active maintenance of stroke volume via increases in inotropy in the presence of decreases in cardiac preload. Baroreflexes retain the ability to regulate blood pressure in many, but not all, heat stress conditions. Central hypovolemia is another cardiovascular challenge brought about by heat stress, which if added to a subsequent central volumetric stress, such as hemorrhage, can be problematic and potentially dangerous, as syncope and cardiovascular collapse may ensue. These combined stresses can compromise blood flow and oxygenation to important tissues such as the brain. It is notable that this compromised condition can occur at cardiac outputs that are adequate during normothermic conditions but are inadequate in heat because of the increased systemic vascular conductance associated with cutaneous vasodilation. Understanding the mechanisms within this complex regulatory system will allow for the development of treatment recommendations and countermeasures to reduce risks during the ever-increasing frequency of severe heat events that are predicted to occur.
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Affiliation(s)
- Craig G Crandall
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and University of Texas Southwestern Medical Center, Dallas, Texas Marian University College of Osteopathic Medicine, Indianapolis, Indiana
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Gifford JR, Ives SJ, Park SY, Andtbacka RHI, Hyngstrom JR, Mueller MT, Treiman GS, Ward C, Trinity JD, Richardson RS. α1- and α2-adrenergic responsiveness in human skeletal muscle feed arteries: the role of TRPV ion channels in heat-induced sympatholysis. Am J Physiol Heart Circ Physiol 2015; 307:H1288-97. [PMID: 25172894 DOI: 10.1152/ajpheart.00068.2014] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The purpose of this study was to determine if heat inhibits α2-adrenergic vasocontraction, similarly to α1-adrenergic contraction, in isolated human skeletal muscle feed arteries (SMFA) and elucidate the role of the temperature-sensitive vanilloid-type transient receptor potential (TRPV) ion channels in this response. Isolated SMFA from 37 subjects were studied using wire myography. α1 [Phenylephrine (PE)]- and α2 [dexmedetomidine (DEX)]-contractions were induced at 37 and 39°C with and without TRPV family and TRPV4-specific inhibition [ruthenium red (RR) and RN-1734, respectively]. Endothelial function [acetylcholine (ACh)] and smooth muscle function [sodium nitroprusside (SNP) and potassium chloride (KCl)] were also assessed under these conditions. Heat and TRPV inhibition was further examined in endothelium-denuded arteries. Contraction data are reported as a percentage of maximal contraction elicited by 100 mM KCl (LTmax). DEX elicited a small and variable contractile response, one-fifth the magnitude of PE, which was not as clearly attenuated when heated from 37 to 39°C (12 ± 4 to 6 ± 2% LTmax; P = 0.18) as were PE-induced contractions (59 ± 5 to 24 ± 4% LTmax; P < 0.05). Both forms of TRPV inhibition restored PE-induced contraction at 39°C (P < 0.05) implicating these channels, particularly the TRPV4 channels, in the heat-induced attenuation of α1-adrenergic vasocontraction. TRPV inhibition significantly blunted ACh relaxation while denudation prevented heat-induced sympatholysis without having an additive effect when combined with TRPV inhibition. In conclusion, physiological increases in temperature elicit a sympatholysis-like inhibition of α1-adrenergic vasocontraction in human SMFA that appears to be mediated by endothelial TRPV4 ion channels.
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Abstract
Environmental temperature can have a surprising impact on extremity growth in homeotherms, but the underlying mechanisms have remained elusive for over a century. Limbs of animals raised at warm ambient temperature are significantly and permanently longer than those of littermates housed at cooler temperature. These remarkably consistent lab results closely resemble the ecogeographical tenet described by Allen's "extremity size rule," that appendage length correlates with temperature and latitude. This phenotypic growth plasticity could have adaptive significance for thermal physiology. Shortened extremities help retain body heat in cold environments by decreasing surface area for potential heat loss. Homeotherms have evolved complex mechanisms to maintain tightly regulated internal temperatures in challenging environments, including "facultative extremity heterothermy" in which limb temperatures can parallel ambient. Environmental modulation of tissue temperature can have direct and immediate consequences on cell proliferation, metabolism, matrix production, and mineralization in cartilage. Temperature can also indirectly influence cartilage growth by modulating circulating levels and delivery routes of essential hormones and paracrine regulators. Using an integrated approach, this article synthesizes classic studies with new data that shed light on the basis and significance of this enigmatic growth phenomenon and its relevance for treating human bone elongation disorders. Discussion centers on the vasculature as a gateway to understanding the complex interconnection between direct (local) and indirect (systemic) mechanisms of temperature-enhanced bone lengthening. Recent advances in imaging modalities that enable the dynamic study of cartilage growth plates in vivo will be key to elucidating fundamental physiological mechanisms of long bone growth regulation.
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Affiliation(s)
- Maria A Serrat
- Department of Anatomy and Pathology, Joan C. Edwards School of Medicine, Marshall University, Huntington, West Virginia
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Schlader ZJ, Rivas E, Soller BR, Convertino VA, Crandall CG. Tissue oxygen saturation during hyperthermic progressive central hypovolemia. Am J Physiol Regul Integr Comp Physiol 2014; 307:R731-6. [PMID: 25031230 DOI: 10.1152/ajpregu.00190.2014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
During normothermia, a reduction in near-infrared spectroscopy (NIRS)-derived tissue oxygen saturation (So2) is an indicator of central hypovolemia. Hyperthermia increases skin blood flow and reduces tolerance to central hypovolemia, both of which may alter the interpretation of tissue So2 during central hypovolemia. This study tested the hypothesis that maximal reductions in tissue So2 would be similar throughout normothermic and hyperthermic central hypovolemia to presyncope. Ten healthy males (means ± SD; 32 ± 5 yr) underwent central hypovolemia via progressive lower-body negative pressure (LBNP) to presyncope during normothermia (skin temperature ≈34°C) and hyperthermia (+1.2 ± 0.1°C increase in internal temperature via a water-perfused suit, skin temperature ≈39°C). NIRS-derived forearm (flexor digitorum profundus) tissue So2 was measured throughout and analyzed as the absolute change from pre-LBNP. Hyperthermia reduced (P < 0.001) LBNP tolerance by 49 ± 33% (from 16.7 ± 7.9 to 7.2 ± 3.9 min). Pre-LBNP, tissue So2 was similar (P = 0.654) between normothermia (74 ± 5%) and hyperthermia (73 ± 7%). Tissue So2 decreased (P < 0.001) throughout LBNP, but the reduction from pre-LBNP to presyncope was greater during normothermia (-10 ± 6%) than during hyperthermia (-6 ± 5%; P = 0.041). Contrary to our hypothesis, these findings indicate that hyperthermia is associated with a smaller maximal reduction in tissue So2 during central hypovolemia to presyncope.
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Affiliation(s)
- Zachary J Schlader
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital of Dallas, Dallas, Texas, and the University of Texas Southwestern Medical Center, Dallas, Texas
| | - Eric Rivas
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital of Dallas, Dallas, Texas, and the University of Texas Southwestern Medical Center, Dallas, Texas; Department of Kinesiology, Texas Woman's University, Denton, Texas
| | - Babs R Soller
- Reflectance Medical Incorporated, Westborough, Massachusetts; Department of Anesthesiology, University of Massachusetts Medical School, Worcester, Massachusetts; and
| | | | - Craig G Crandall
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital of Dallas, Dallas, Texas, and the University of Texas Southwestern Medical Center, Dallas, Texas;
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Bharath LP, Mueller R, Li Y, Ruan T, Kunz D, Goodrich R, Mills T, Deeter L, Sargsyan A, Anandh Babu PV, Graham TE, Symons JD. Impairment of autophagy in endothelial cells prevents shear-stress-induced increases in nitric oxide bioavailability. Can J Physiol Pharmacol 2014; 92:605-12. [PMID: 24941409 DOI: 10.1139/cjpp-2014-0017] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Autophagy is a lysosomal catabolic process by which cells degrade or recycle their contents to maintain cellular homeostasis, adapt to stress, and respond to disease. Impairment of autophagy in endothelial cells studied under static conditions results in oxidant stress and impaired nitric oxide (NO) bioavailability. We tested the hypothesis that vascular autophagy is also important for induction of NO production caused by exposure of endothelial cells to shear stress (i.e., 3 h × ≈20 dyn/cm(2)). Atg3 is a requisite autophagy pathway mediator. Control cells treated with non-targeting control siRNA showed increased autophagy, reactive oxygen species (ROS) production, endothelial NO synthase (eNOS) phosphorylation, and NO production upon exposure to shear stress (p < 0.05 for all). In contrast, cells with >85% knockdown of Atg3 protein expression (via Atg3 siRNA) exhibited a profound impairment of eNOS phosphorylation, and were incapable of increasing NO in response to shear stress. Moreover, ROS accumulation and inflammatory cytokine production (MCP-1 and IL-8) were exaggerated (all p < 0.05) in response to shear stress. These findings reveal that autophagy not only plays a critical role in maintaining NO bioavailability, but may also be a key regulator of oxidant-antioxidant balance and inflammatory-anti-inflammatory balance that ultimately regulate endothelial cell responses to shear stress.
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Affiliation(s)
- Leena P Bharath
- a College of Health, University of Utah, Salt Lake City, UT 84112, USA
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Jendzjowsky NG, DeLorey DS. Short-term exercise training augments 2-adrenoreceptor-mediated sympathetic vasoconstriction in resting and contracting skeletal muscle. J Physiol 2013; 591:5221-33. [PMID: 23940382 DOI: 10.1113/jphysiol.2013.257626] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
We hypothesized that exercise training (ET) would alter α2-adrenoreceptor-mediated sympathetic vasoconstriction. Sprague-Dawley rats (n = 30) were randomized to sedentary (S), mild- (M) or heavy-intensity (H) treadmill ET groups (5 days per week for 4 weeks). Following the ET component of the study, rats were anaesthetized, and instrumented for lumbar sympathetic chain stimulation, triceps surae muscle contraction and measurement of femoral vascular conductance (FVC). The percentage change of FVC in response to sympathetic stimulation was determined at rest and during contraction in control, α2 blockade (yohimbine) and combined α2 + nitric oxide (NO) synthase (NOS) blockade (N-nitro-L-arginine methyl ester hydrochloride, L-NAME) conditions. ET augmented (P < 0.05) sympathetic vasoconstrictor responses at rest and during contraction. Yohimbine reduced (P < 0.05) the vasoconstrictor response in ET rats at rest (M: 2 Hz: 8 ± 2%, 5 Hz: 9 ± 4%; H: 2 Hz: 14 ± 5%, 5 Hz: 11 ± 6%) and during contraction (M: 2 Hz: 9 ± 2%, 5 Hz: 9 ± 5%; H: 2 Hz: 8 ± 3%, 5 Hz: 6 ± 6%) but did not change the response in S rats. The addition of L-NAME caused a larger increase (P < 0.05) in the vasoconstrictor response in ET than in S rats at rest (2 Hz: S: 8 ± 2%, M: 15 ± 3%, H: 23 ± 7%; 5 Hz: S: 8 ± 5%, M: 15 ± 3%, H: 17 ± 5%) and during contraction (2 Hz: S: 9 ± 3%, M: 18 ± 3%, H: 22 ± 6%; 5 Hz: S: 9 ± 5%, M: 22 ± 4%, H:26 ± 9%). Sympatholysis was greater (P < 0.05) in ET than in S rats. Blockade of α2-adrenoreceptors and NOS reduced (P < 0.05) sympatholysis in ET rats, but had no effect on sympatholysis in S rats. In conclusion, ET increased α2-mediated vasoconstriction at rest and during contraction.
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Affiliation(s)
- Nicholas G Jendzjowsky
- Darren S. DeLorey: Faculty of Physical Education and Recreation, University of Alberta, E-435 Van Vliet Centre, Edmonton, T6G 2H9, Alberta, Canada.
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Jammes Y, Steinberg JG, Olivier M, Brerro-Saby C, Condo J, Ravailhe S, Guieu R, Delliaux S. The mechanisms of the widespread production of phosphorylated HSP25 after fatiguing muscle stimulation. ACTA ACUST UNITED AC 2013; 216:3620-6. [PMID: 23788701 DOI: 10.1242/jeb.088898] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
We previously showed that a widespread heat shock protein (HSP) response to fatigue of a single hindlimb muscle was responsible for a global adaptive response to an acute localized stress. We also demonstrated that the HSP response resulted from the activation of nerve afferents from the stimulated muscle. However, we did not examine the role played by the different muscle afferents or the efferent arm of HSP response. In the present study we measured the changes in phosphorylated HSP25 (pHSP25) levels in resting hindlimb muscles and the diaphragm, kidney and brain in response to a fatiguing stimulation of one tibialis anterior muscle that was repeated in five series of experiments: (1) intact muscle innervation, (2) during the selective procaine block of conduction in group IV muscle afferents, (3) after muscle nerve transection to suppress all the sensory messages, and under pharmacological blockade of the (4) alpha-adrenergic or (5) glutamatergic neurotransmission. The data showed that: (1) the pHSP25 response in hindlimb muscles resulted from the stimulation of both group III and IV muscle afferents while the pHSP25 response in the diaphragm, kidney and brain resulted from the sole activation of the group IV fibres, and (2) the blockade of alpha-adrenergic, but not glutamatergic, neurotransmission suppressed the pHSP25 response in all explored tissues except the brain. The present study highlights the role played by the group III and IV muscle afferents in the fatigue-induced pHSP25 response and shows that the sympathetic nerve supply to the muscles and kidney represents the efferent arm of the pHSP25 activation. However, the pHSP25 changes in the brain cannot be explained by the pathways investigated here.
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Affiliation(s)
- Yves Jammes
- UMR MD2, Faculty of Medicine, Aix-Marseille University, Boulevard Pierre Dramard, 13916 cedex 20, Marseille, France.
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