1
|
Iepsen UW, Hjortdal AR, Thuesen AD, Finsen SH, Hansen PBL, Mortensen SP. The role of T-type calcium channels in elderly human vascular function: A pilot randomized controlled trial. Exp Physiol 2024; 109:779-790. [PMID: 38445814 PMCID: PMC11061624 DOI: 10.1113/ep091645] [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: 11/06/2023] [Accepted: 02/13/2024] [Indexed: 03/07/2024]
Abstract
Endothelial dysfunction develops with age and may precede cardiovascular disease. Animal data suggest that T-type calcium channels play an important role in endothelial function, but data from humans are lacking. This study included 15 healthy, sedentary, elderly males for a double blinded, randomized controlled trial. For 8 weeks, they were given 40 mg/day of either efonidipine (L- and T-type calcium channel blocker (CCB)) or nifedipine (L-type CCB). Vascular function was evaluated by graded femoral arterial infusions of acetylcholine (ACh; endothelium-dependent vasodilator) and sodium nitroprusside (endothelium-independent vasodilator) both with and without co-infusion of N-acetylcysteine (NAC; antioxidant). We measured leg blood flow and mean arterial pressure and calculated leg vascular conductance to evaluate the leg vascular responses. Despite no significant change in blood pressure in either group, we observed higher leg blood flow responses (Δ 0.43 ± 0.45 l/min, P = 0.006) and leg vascular conductance (Δ 5.38 ± 5.67 ml/min/mmHg, P = 0.005) to intra-arterial ACh after efonidipine, whereas there was no change in the nifedipine group, and no differences between groups. We found no upregulation of endothelial nitric oxide synthase in vastus lateralis muscle biopsies within or between groups. Smooth muscle cell responsiveness was unaltered by efonidipine or nifedipine. Intravenous co-infusion of NAC did not affect endothelium-dependent vasodilatation in either of the CCB groups. These results suggest that 8 weeks' inhibition of T- and L-type calcium channels augments endothelium-dependent vasodilatory function in healthy elderly males. Further studies are required to elucidate if T-type calcium channel inhibition can counteract endothelial dysfunction.
Collapse
Affiliation(s)
- Ulrik Winning Iepsen
- Center for Physical Activity ResearchCopenhagen University Hospital – RigshospitaletCopenhagenDenmark
- Department of Anaesthesia and Intensive CareCopenhagen University Hospital – Hvidovre HospitalCopenhagenDenmark
| | - Andreas R. Hjortdal
- Center for Physical Activity ResearchCopenhagen University Hospital – RigshospitaletCopenhagenDenmark
| | - Anne D. Thuesen
- Department of Cardiovascular and Renal ResearchUniversity of Southern DenmarkOdenseDenmark
| | - Stine H. Finsen
- Department of Cardiovascular and Renal ResearchUniversity of Southern DenmarkOdenseDenmark
| | - Pernille B. L. Hansen
- Department of Cardiovascular and Renal ResearchUniversity of Southern DenmarkOdenseDenmark
| | - Stefan P. Mortensen
- Department of Cardiovascular and Renal ResearchUniversity of Southern DenmarkOdenseDenmark
| |
Collapse
|
2
|
Five Days of Tart Cherry Supplementation Improves Exercise Performance in Normobaric Hypoxia. Nutrients 2023; 15:nu15020388. [PMID: 36678258 PMCID: PMC9864878 DOI: 10.3390/nu15020388] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 01/08/2023] [Accepted: 01/10/2023] [Indexed: 01/15/2023] Open
Abstract
Previous studies have shown tart cherry (TC) to improve exercise performance in normoxia. The effect of TC on hypoxic exercise performance is unknown. This study investigated the effects of 5 days of tart cherry (TC) or placebo (PL) supplementation on hypoxic exercise performance. Thirteen healthy participants completed an incremental cycle exercise test to exhaustion (TTE) under two conditions: (i) hypoxia (13% O2) with PL and (ii) hypoxia with TC (200 mg anthocyanin per day for 4 days and 100 mg on day 5). Pulmonary gas exchange variables, peripheral arterial oxygen saturation (SpO2), deoxygenated hemoglobin (HHb), and tissue oxygen saturation (StO2) assessed by near-infrared spectroscopy in the vastus lateralis muscle were measured at rest and during exercise. Urinary 8-hydro-2′ deoxyguanosine (8-OHdG) excretion was evaluated pre-exercise and 1 and 5 h post-exercise. The TTE after TC (940 ± 84 s, mean ± standard deviation) was longer than after PL (912 ± 63 s, p < 0.05). During submaximal hypoxic exercise, HHb was lower and StO2 and SpO2 were higher after TC than PL. Moreover, a significant interaction (supplements × time) in urinary 8-OHdG excretion was found (p < 0.05), whereby 1 h post-exercise increases in urinary 8-OHdG excretion tended to be attenuated after TC. These findings indicate that short-term dietary TC supplementation improved hypoxic exercise tolerance, perhaps due to lower HHb and higher StO2 in the working muscles during submaximal exercise.
Collapse
|
3
|
Hogwood AC, Decker KP, Darling AM, Weggen JB, Chiu A, Richardson J, Garten RS. Exaggerated pressor responses, but unaltered blood flow regulation and functional sympatholysis during lower limb exercise in young, non-Hispanic black males. Microvasc Res 2023; 145:104445. [PMID: 36209773 DOI: 10.1016/j.mvr.2022.104445] [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: 08/03/2022] [Revised: 10/03/2022] [Accepted: 10/03/2022] [Indexed: 11/05/2022]
Abstract
PURPOSE Young non-Hispanic black (BL) males have displayed lower blood flow (BF) and vascular conductance (VC), but intact functional sympatholysis, during upper limb exercise when compared to non-Hispanic white (WH) males. This study sought to explore if similar differences were also present in the lower limbs. METHODS Thirteen young BL males and thirteen WH males completed one visit comprised of rhythmic lower limb (plantar flexion) exercise as well as upper limb (handgrip) exercise for a limb-specific comparison. Limb BF, mean arterial pressure (MAP), and VC were evaluated at three submaximal workloads (8, 16, and 24 kg). To determine potential limb differences in functional sympatholysis, the impact of sympathetic nervous system activation (via cold-pressor test (CPT)) was evaluated at rest and during steady state exercise (30 % of maximal voluntary contraction) on a subsequent visit. RESULTS MAP responses to lower and upper limb exercise were elevated in young BL males (vs WH males), resulting in significantly lower VC responses in the upper limb, but not the lower limb. Further, BL males, when compared to WH males, revealed no differences in functional sympatholysis, evident by similar responses in both the exercising leg and arm VC during CPT. CONCLUSION The findings of the current study indicate that although elevated MAP responses were observed during both lower and upper limb exercise in young BL males, vascular conductance was only hindered in the upper limbs. This may potentially highlight enhanced compensatory mechanisms in the lower limb (vs upper limb) to maintain perfusion in young BL males.
Collapse
Affiliation(s)
- Austin C Hogwood
- Department of Kinesiology, University of Virginia, Charlottesville, VA, USA
| | - Kevin P Decker
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE, USA
| | - Ashley M Darling
- Department of Kinesiology, University of Texas at Arlington, Arlington, TX, USA
| | - Jennifer B Weggen
- Department of Kinesiology and Health Sciences, Virginia Commonwealth University, Richmond, VA, USA
| | - Alex Chiu
- Department of Kinesiology and Health Sciences, Virginia Commonwealth University, Richmond, VA, USA
| | - Jacob Richardson
- Department of Kinesiology and Health Sciences, Virginia Commonwealth University, Richmond, VA, USA
| | - Ryan S Garten
- Department of Kinesiology and Health Sciences, Virginia Commonwealth University, Richmond, VA, USA.
| |
Collapse
|
4
|
Fermoyle CC, Broxterman RM, La Salle DT, Ratchford SM, Hopkins PN, Richardson RS, Trinity JD. Persistent vascular dysfunction following an acute nonpharmacological reduction in blood pressure in hypertensive patients. J Hypertens 2022; 40:1115-1125. [PMID: 35703879 PMCID: PMC9204754 DOI: 10.1097/hjh.0000000000003104] [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] [Indexed: 11/27/2022]
Abstract
BACKGROUND Vascular dysfunction, an independent risk factor for cardiovascular disease, often persists in patients with hypertension, despite improvements in blood pressure control induced by antihypertensive medications. METHODS As some of these medications may directly affect vascular function, this study sought to comprehensively examine the impact of reducing blood pressure, by a nonpharmacological approach (5 days of sodium restriction), on vascular function in 22 hypertensive individuals (14 men/8 women, 50 ± 10 years). Following a 2-week withdrawal of antihypertensive medications, two 5-day dietary phases, liberal sodium (liberal sodium, 200 mmol/day) followed by restricted sodium (restricted sodium, 10 mmol/day), were completed. Resting blood pressure was assessed and vascular function, at both the conduit and microvascular levels, was evaluated by brachial artery flow-mediated dilation (FMD), reactive hyperemia, progressive handgrip exercise, and passive leg movement (PLM). RESULTS Despite a sodium restriction-induced fall in blood pressure (liberal sodium: 141 ± 14/85 ± 9; restricted sodium 124 ± 12/79 ± 9 mmHg, P < 0.01 for both SBP and DBP), FMD (liberal sodium: 4.6 ± 1.8%; restricted sodium: 5.1 ± 2.1%, P = 0.27), and reactive hyperemia (liberal sodium: 548 ± 201; restricted sodium: 615 ± 206 ml, P = 0.08) were not altered. Similarly, brachial artery vasodilation during handgrip exercise was not different between conditions (liberal sodium: Δ0.36 ± 0.19 mm; restricted sodium: Δ0.42 ± 0.18 mm, P = 0.16). Lastly, PLM-induced changes in peak blood flow (liberal sodium: 5.3 ± 2.5; restricted sodium: 5.8 ± 3.6 ml/min per mmHg, P = 0.30) and the total vasodilatory response [liberal sodium: 2 (0.9-2.5) vs. restricted sodium: 1.7 (1.1-2.6) ml/min per mmHg; P = 0.5] were also not different between conditions. CONCLUSION Thus vascular dysfunction, at both the conduit and microvascular levels, persists in patients with hypertension even when blood pressure is acutely reduced by a nonpharmacological approach.
Collapse
Affiliation(s)
- Caitlin C Fermoyle
- Geriatric Research, Education, and Clinical Center, George E. Whalen VA Medical Center
- Division of Geriatrics, Department of Internal Medicine
| | - Ryan M Broxterman
- Geriatric Research, Education, and Clinical Center, George E. Whalen VA Medical Center
- Division of Geriatrics, Department of Internal Medicine
| | | | - Stephen M Ratchford
- Geriatric Research, Education, and Clinical Center, George E. Whalen VA Medical Center
- Division of Geriatrics, Department of Internal Medicine
| | - Paul N Hopkins
- Division of Cardiovascular Genetics, Department of Internal Medicine, University of Utah, Salt Lake City, Utah, USA
| | - Russell S Richardson
- Geriatric Research, Education, and Clinical Center, George E. Whalen VA Medical Center
- Division of Geriatrics, Department of Internal Medicine
- Department of Nutrition and Integrative Physiology
| | - Joel D Trinity
- Geriatric Research, Education, and Clinical Center, George E. Whalen VA Medical Center
- Division of Geriatrics, Department of Internal Medicine
- Department of Nutrition and Integrative Physiology
| |
Collapse
|
5
|
Machin DR, Clifton HL, Wray DW, Frech TM, Donato AJ. Tetrahydrobiopterin Administration Augments Exercise-Induced Hyperemia and Endothelial Function in Patients With Systemic Sclerosis. Front Med (Lausanne) 2022; 8:791689. [PMID: 35083247 PMCID: PMC8784551 DOI: 10.3389/fmed.2021.791689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 12/08/2021] [Indexed: 11/13/2022] Open
Abstract
Systemic sclerosis (SSc) is a rare, auto-immune disease with variably progressive fibrosis of the skin and internal organs, as well as vascular dysfunction. Recently, we demonstrated a decrement in exercising skeletal muscle blood flow and endothelium-dependent vasodilation in SSc, but the mechanisms responsible for these impairments have not been investigated. Thus, we sought to determine if acute administration of tetrahydrobiopterin (BH4), an essential cofactor for endothelial nitric oxide synthase (eNOS), would improve hyperemia and brachial artery vasodilation during progressive handgrip exercise in SSc. Thirteen patients with SSc (63 ± 11 years) participated in this placebo-controlled, randomized, double-blind, crossover study. Tetrahydrobiopterin (10 mg/kg) administration resulted in a ~4-fold increase in circulating BH4 concentrations (P < 0.05). Cardiovascular variables at rest were unaffected by BH4 (P > 0.05). During handgrip exercise, BH4 administration increased brachial artery blood flow (placebo: 200 ± 87; BH4: 261 ± 115 ml/min; P < 0.05) and vascular conductance (placebo: 2.0 ± 0.8; BH4: 2.5 ± 1.0 ml/min/mmHg; P < 0.05), indicating augmented resistance artery vasodilation. Tetrahydrobiopterin administration also increased brachial artery vasodilation in response to exercise (placebo: 12 ± 6; BH4: 17 ± 7%; P < 0.05), resulting in a significant upward shift in the slope relationship between Δ brachial artery vasodilation and Δ shear rate (placebo: 0.030 ± 0.007; BH4: 0.047 ± 0.007; P < 0.05) that indicates augmented sensitivity of the brachial artery to vasodilate to the sustained elevations in shear rate during handgrip exercise. These results demonstrate the efficacy of acute BH4 administration to improve both resistance and conduit vessel endothelial function in SSc, suggesting that eNOS recoupling may be an effective strategy for improving vasodilatory capacity in this patient group.
Collapse
Affiliation(s)
- Daniel R Machin
- Department of Internal Medicine, University of Utah, Salt Lake City, UT, United States.,Geriatric Research Education and Clinical Center, VA Salt Lake City, Salt Lake City, UT, United States.,Department of Nutrition and Integrative Physiology, Florida State University, Tallahassee, FL, United States
| | - Heather L Clifton
- Geriatric Research Education and Clinical Center, VA Salt Lake City, Salt Lake City, UT, United States
| | - D Walter Wray
- Department of Internal Medicine, University of Utah, Salt Lake City, UT, United States.,Geriatric Research Education and Clinical Center, VA Salt Lake City, Salt Lake City, UT, United States.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, United States
| | - Tracy M Frech
- Department of Internal Medicine, University of Utah, Salt Lake City, UT, United States.,Department of Internal Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Anthony J Donato
- Department of Internal Medicine, University of Utah, Salt Lake City, UT, United States.,Geriatric Research Education and Clinical Center, VA Salt Lake City, Salt Lake City, UT, United States.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, United States.,Department of Biochemistry, University of Utah, Salt Lake City, UT, United States
| |
Collapse
|
6
|
Ascorbic Acid Significantly Decreases Creatine Kinase Plasma Levels in an Animal Model of Statin/Fibrate-Induced Myopathy. Adv Pharmacol Pharm Sci 2022; 2021:5539595. [PMID: 35005624 PMCID: PMC8731278 DOI: 10.1155/2021/5539595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 11/18/2021] [Accepted: 11/22/2021] [Indexed: 11/17/2022] Open
Abstract
Background Myopathy is one of the side effects of lipid-lowering drugs, especially statins and particularly when combined with a fibrate. To diagnose myopathy and determine its severity, the plasma levels of three enzymes, creatine kinase (CK), aldolase, and lactate dehydrogenase (LDH), are routinely measured. Physical exercise can aggravate the statin-associated muscular disease. The question is whether antioxidants like ascorbic acid (Vit. C) can prevent such myopathy. Methods In this experiment, a combination of atorvastatin (ATV, 80 mg/kg/day) and gemfibrozil (GMF, 1000 mg/kg/day) orally for 10 days as well as exercise as forced swimming on days 8, 9, and 10 were used to induce myopathy. Ascorbic acid (50 mg/kg/day, orally) was added to ATV/GMF plus exercise regimen throughout the 10 days in the treatment group. Mean blood levels of CK, aldolase, and LDH were measured in addition to swimming tolerance times. Results There was a significantly higher swimming tolerance time (P < 0.05) and lower CK levels (P < 0.01) in rats receiving ATV/GMF/Vit. C plus exercise compared with rats not taking Vit. C. LDH and aldolase did not decrease significantly. Conclusion The results of this study showed that Vit. C can be effective in preventing myopathy caused by fat-lowering drugs.
Collapse
|
7
|
Lefferts EC, Hibner BA, Lefferts WK, Lima NS, Baynard T, Haus JM, Lane‐Cordova AD, Phillips SA, Fernhall B. Oral vitamin C restores endothelial function during acute inflammation in young and older adults. Physiol Rep 2021; 9:e15104. [PMID: 34762777 PMCID: PMC8582295 DOI: 10.14814/phy2.15104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 10/14/2021] [Indexed: 11/24/2022] Open
Abstract
Oxidative stress has been linked to reductions in vascular function during acute inflammation in young adults; however, the effect of acute inflammation on vascular function with aging is inconclusive. The aim of this study was to determine if oral antioxidant administration eliminates vascular dysfunction during acute inflammation in young and older adults. Brachial flow-mediated dilation (FMD) and carotid-femoral pulse wave velocity (PWV) were measured in nine young (3 male, 24 ± 4 yrs, 26.2 ± 4.9 kg/m2 ) and 16 older (13 male, 64 ± 5 yrs, 25.8 ± 3.2 kg/m2 ) adults before and 2-h after oral consumption of 2 g of vitamin C. The vitamin C protocol was completed at rest and 24 h after acute inflammation was induced via the typhoid vaccine. Venous blood samples were taken to measure markers of inflammation and vitamin C. Both interleukin-6 (Δ+0.7 ± 1.8 pg/ml) and C-reactive protein (Δ+1.9 ± 3.1 mg/L) were increased at 24 h following the vaccine (p < 0.01). There was no change in FMD or PWV following vitamin C administration at rest (p > 0.05). FMD was lower in all groups during acute inflammation (Δ-1.4 ± 1.9%, p < 0.01), with no changes in PWV (Δ-0.0 ± 0.9 m/s, p > 0.05). Vitamin C restored FMD back to initial values in young and older adults during acute inflammation (Δ+1.0 ± 1.8%, p < 0.01) with no change in inflammatory markers or PWV (p > 0.05). In conclusion, oral vitamin C restored endothelial function during acute inflammation in young and older adults, with no effect on aortic stiffness. The effect of vitamin C on endothelial function did not appear to be due to reductions in inflammatory markers. The exact mechanisms should be further investigated.
Collapse
Affiliation(s)
- Elizabeth C. Lefferts
- Department of Kinesiology and NutritionUniversity of Illinois at ChicagoChicagoIllinoisUSA
- Department of KinesiologyIowa State UniversityAmesIowaUSA
| | - Brooks A. Hibner
- Department of Kinesiology and NutritionUniversity of Illinois at ChicagoChicagoIllinoisUSA
| | - Wesley K. Lefferts
- Department of Kinesiology and NutritionUniversity of Illinois at ChicagoChicagoIllinoisUSA
- Department of KinesiologyIowa State UniversityAmesIowaUSA
| | - Natalia S. Lima
- Department of Kinesiology and NutritionUniversity of Illinois at ChicagoChicagoIllinoisUSA
| | - Tracy Baynard
- Department of Kinesiology and NutritionUniversity of Illinois at ChicagoChicagoIllinoisUSA
| | - Jacob M. Haus
- School of KinesiologyUniversity of MichiganAnn ArborMichiganUSA
| | - Abbi D. Lane‐Cordova
- Department of Exercise ScienceArnold School of Public HealthUniversity of South CarolinaColumbiaSouth CarolinaUSA
| | - Shane A. Phillips
- Department of Physical TherapyUniversity of Illinois at ChicagoChicagoIllinoisUSA
| | - Bo Fernhall
- Department of Kinesiology and NutritionUniversity of Illinois at ChicagoChicagoIllinoisUSA
| |
Collapse
|
8
|
Ranadive SM, Dillon GA, Mascone SE, Alexander LM. Vascular Health Triad in Humans With Hypertension-Not the Usual Suspects. Front Physiol 2021; 12:746278. [PMID: 34658930 PMCID: PMC8517241 DOI: 10.3389/fphys.2021.746278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 08/25/2021] [Indexed: 11/13/2022] Open
Abstract
Hypertension (HTN) affects more than one-third of the US population and remains the top risk factor for the development of cardiovascular disease (CVD). Identifying the underlying mechanisms for developing HTN are of critical importance because the risk of developing CVD doubles with ∼20 mmHg increase in systolic blood pressure (BP). Endothelial dysfunction, especially in the resistance arteries, is the primary site for initiation of sub-clinical HTN. Furthermore, inflammation and reactive oxygen and nitrogen species (ROS/RNS) not only influence the endothelium independently, but also have a synergistic influence on each other. Together, the interplay between inflammation, ROS and vascular dysfunction is referred to as the vascular health triad, and affects BP regulation in humans. While the interplay of the vascular health triad is well established, new underlying mechanistic targets are under investigation, including: Inducible nitric oxide synthase, hydrogen peroxide, hydrogen sulfide, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and nuclear factor activated T cells. This review outlines the role of these unusual suspects in vascular health and function in humans. This review connects the dots using these unusual suspects underlying inflammation, ROS and vascular dysfunction especially in individuals at risk of or with diagnosed HTN based on novel studies performed in humans.
Collapse
Affiliation(s)
- Sushant M Ranadive
- Department of Kinesiology, University of Maryland, College Park, College Park, MD, United States
| | - Gabrielle A Dillon
- Department of Kinesiology, The Pennsylvania State University, University Park, PA, United States.,Center for Healthy Aging, The Pennsylvania State University, University Park, PA, United States
| | - Sara E Mascone
- Department of Kinesiology, University of Maryland, College Park, College Park, MD, United States
| | - Lacy M Alexander
- Department of Kinesiology, The Pennsylvania State University, University Park, PA, United States.,Center for Healthy Aging, The Pennsylvania State University, University Park, PA, United States
| |
Collapse
|
9
|
King TJ, Coates AM, Tremblay JC, Slysz JT, Petrick HL, Pignanelli C, Millar PJ, Burr JF. Vascular Function Is Differentially Altered by Distance after Prolonged Running. Med Sci Sports Exerc 2021; 53:597-605. [PMID: 32804900 DOI: 10.1249/mss.0000000000002493] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
PURPOSE Ultraendurance exercise is steadily growing in popularity; however, the effect of increasingly prolonged durations of exercise on the vascular endothelium is unknown. The aim of this study was to characterize the effect of various ultramarathon running distances on vascular form and function. METHODS We evaluated vascular endothelial function via flow-mediated dilation (FMD) in the superficial femoral artery, as well as microvascular function, inflammatory factors, and central artery stiffness, before and after participants completed 25-km (7M:2F), 50-km (11M:10F), 80-km (9M:4F), or 160-km (9M:2F) trail races all run on the same day and course. RESULTS Completion required 149 ± 20, 386 ± 111, 704 ± 130, and 1470 ± 235 min, with corresponding average paces of 6.0 ± 0.8, 7.7 ± 2.2, 8.6 ± 1.3, and 9.6 ± 1.3 min·km-1, respectively. At baseline, there were no differences in participant characteristics across race distance groups. Shear rate stimulus trended toward an increase after the race (P = 0.07), but resting postrace artery diameter (P < 0.001) was elevated to a similar extent in all conditions. There was a reduction in FMD after the 50-km race (Δ -1.9% ± 2.2%, P < 0.01), but not the 25-km (Δ +0.3% ± 2.9%, P = 0.8), the 80-km (Δ -1.5% ± 3.2%, P = 0.1), or the 160-km (Δ +0.5% ± 2.5%, P = 0.5) race. Inflammatory markers increased most after 160 km, but arterial stiffness and microvascular function were not differently affected by race distance. CONCLUSIONS Although the superficial femoral artery baseline diameter was larger postexercise regardless of race distance, only the 50-km race reduced FMD, whereas a short-duration higher-intensity race (25 km) and longer-duration lower-intensity races (160 km) did not. Therefore, a 50-km ultramarathon may represent the intersection between higher-intensity exercise over a prolonged duration, causing reduced endothelial function not seen in shorter or longer distances.
Collapse
Affiliation(s)
- Trevor J King
- Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, CANADA
| | - Alexandra M Coates
- Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, CANADA
| | - Joshua C Tremblay
- School of Kinesiology and Health Studies, Queen's University, Kingston, ON, CANADA
| | - Joshua T Slysz
- Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, CANADA
| | - Heather L Petrick
- Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, CANADA
| | | | - Philip J Millar
- Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, CANADA
| | - Jamie F Burr
- Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, CANADA
| |
Collapse
|
10
|
Viggiano A, Ponticorvo S, Canna A, Secondulfo C, Sbordone L, Russo A, Monda M, Di Salle F, Esposito F. Vitamin C Acutely Affects Brain Perfusion and Mastication-Induced Perfusion Asymmetry in the Principal Trigeminal Nucleus. Front Syst Neurosci 2021; 15:641121. [PMID: 33716681 PMCID: PMC7953051 DOI: 10.3389/fnsys.2021.641121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Accepted: 02/03/2021] [Indexed: 11/13/2022] Open
Abstract
Prolonged mastication may induce an asymmetric modification of the local perfusion of the trigeminal principal nucleus. The aim of the present study was to evaluate the possible influence of vitamin C (vit. C) on such effect. Four groups of healthy volunteers underwent arterial spin labeling magnetic resonance imaging (ASL-MRI) to evaluate the local perfusion of the trigeminal nuclei after a vit. C-enriched lunch or a control lunch. Two ASL-MRI scans were acquired, respectively, before and after a 1 h-long masticating exercise or a 1 h long resting period. The results showed (i) an increased global perfusion of the brain in the vit. C-enriched lunch groups, (ii) an increased local perfusion of the right principal trigeminal nucleus (Vp) due to mastication, and (iii) a reduction of the rightward asymmetry of the Vp perfusion, due to mastication, after the vit C-enriched meal compared to the control meal. These results confirmed a long-lasting effect of prolonged mastication on Vp perfusion and also suggest a possible effect of vit. C on cerebral vascular tone regulation. Moreover, the data strongly draw attention on the side-to-side relation in Vp perfusion as a possible physiological parameter to be considered to understand the origin of pathological conditions like migraine.
Collapse
Affiliation(s)
- Andrea Viggiano
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Baronissi, Italy
| | - Sara Ponticorvo
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Baronissi, Italy
| | - Antonietta Canna
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Baronissi, Italy
| | - Carmine Secondulfo
- University Hospital "San Giovanni di Dio e Ruggi D'Aragona", Salerno, Italy
| | - Ludovico Sbordone
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Baronissi, Italy.,University Hospital "San Giovanni di Dio e Ruggi D'Aragona", Salerno, Italy
| | - Antonio Russo
- Department of Advanced Medical and Surgical Sciences, University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Marcellino Monda
- Section of Human Physiology, Unit of Dietetic and Sport Medicine, Department of Experimental Medicine, University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Francesco Di Salle
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Baronissi, Italy.,University Hospital "San Giovanni di Dio e Ruggi D'Aragona", Salerno, Italy
| | - Fabrizio Esposito
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Baronissi, Italy.,University Hospital "San Giovanni di Dio e Ruggi D'Aragona", Salerno, Italy.,Department of Advanced Medical and Surgical Sciences, University of Campania "Luigi Vanvitelli", Naples, Italy
| |
Collapse
|
11
|
Rezk-Hanna M, Seals DR, Rossman MJ, Gupta R, Nettle CO, Means A, Dobrin D, Cheng CW, Brecht ML, Mosenifar Z, Araujo JA, Benowitz NL. Ascorbic Acid Prevents Vascular Endothelial Dysfunction Induced by Electronic Hookah (Waterpipe) Vaping. J Am Heart Assoc 2021; 10:e019271. [PMID: 33615833 PMCID: PMC8174254 DOI: 10.1161/jaha.120.019271] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Background Electronic hookah (e‐hookah) vaping has increased in popularity among youth, who endorse unsubstantiated claims that flavored aerosol is detoxified as it passes through water. However, e‐hookahs deliver nicotine by creating an aerosol of fine and ultrafine particles and other oxidants that may reduce the bioavailability of nitric oxide and impair endothelial function secondary to formation of oxygen‐derived free radicals. Methods and Results We examined the acute effects of e‐hookah vaping on endothelial function, and the extent to which increased oxidative stress contributes to the vaping‐induced vascular impairment. Twenty‐six healthy young adult habitual hookah smokers were invited to vape a 30‐minute e‐hookah session to evaluate the impact on endothelial function measured by brachial artery flow‐mediated dilation (FMD). To test for oxidative stress mediation, plasma total antioxidant capacity levels were measured and the effect of e‐hookah vaping on FMD was examined before and after intravenous infusion of the antioxidant ascorbic acid (n=11). Plasma nicotine and exhaled carbon monoxide levels were measured before and after the vaping session. Measurements were performed before and after sham‐vaping control experiments (n=10). E‐hookah vaping, which increased plasma nicotine (+4.93±0.92 ng/mL, P<0.001; mean±SE) with no changes in exhaled carbon monoxide (−0.15±0.17 ppm; P=0.479), increased mean arterial pressure (11±1 mm Hg, P<0.001) and acutely decreased FMD from 5.79±0.58% to 4.39±0.46% (P<0.001). Ascorbic acid infusion, which increased plasma total antioxidant capacity 5‐fold, increased FMD at baseline (5.98±0.66% versus 9.46±0.87%, P<0.001), and prevented the acute FMD impairment by e‐hookah vaping (9.46±0.87% versus 8.74±0.84%, P=0.002). All parameters were unchanged during sham studies. Conclusions E‐hookah vaping has adverse effects on vascular function, likely mediated by oxidative stress, which overtime could accelerate development and progression of cardiovascular disease. Registration URL: https://ClinicalTrials.gov. Unique identifier: NCT03690427.
Collapse
Affiliation(s)
| | - Douglas R Seals
- Department of Integrative Physiology University of Colorado Boulder Boulder CO
| | - Matthew J Rossman
- Department of Integrative Physiology University of Colorado Boulder Boulder CO
| | - Rajat Gupta
- Division of Cardiology Department of Medicine David Geffen School of Medicine at University of California Los Angeles CA
| | | | - Angelica Means
- School of Nursing University of California Los Angeles CA
| | - Daniel Dobrin
- School of Nursing University of California Los Angeles CA
| | | | | | - Zab Mosenifar
- Division of Pulmonary and Critical Care MedicineCedars-Sinai Medical Center Los Angeles CA
| | - Jesus A Araujo
- Division of Cardiology Department of Medicine David Geffen School of Medicine at University of California Los Angeles CA.,Department of Environmental Health Sciences Fielding School of Public Health University of California Los Angeles CA
| | - Neal L Benowitz
- Clinical Pharmacology Research Program Division of Cardiology Department of Medicine University of California San Francisco CA
| |
Collapse
|
12
|
Mason SA, Trewin AJ, Parker L, Wadley GD. Antioxidant supplements and endurance exercise: Current evidence and mechanistic insights. Redox Biol 2020; 35:101471. [PMID: 32127289 PMCID: PMC7284926 DOI: 10.1016/j.redox.2020.101471] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 02/11/2020] [Accepted: 02/17/2020] [Indexed: 01/07/2023] Open
Abstract
Antioxidant supplements are commonly consumed by endurance athletes to minimize exercise-induced oxidative stress, with the intention of enhancing recovery and improving performance. There are numerous commercially available nutritional supplements that are targeted to athletes and health enthusiasts that allegedly possess antioxidant properties. However, most of these compounds are poorly investigated with respect to their in vivo redox activity and efficacy in humans. Therefore, this review will firstly provide a background to endurance exercise-related redox signalling and the subsequent adaptations in skeletal muscle and vascular function. The review will then discuss commonly available compounds with purported antioxidant effects for use by athletes. N-acetyl cysteine may be of benefit over the days prior to an endurance event; while chronic intake of combined 1000 mg vitamin C + vitamin E is not recommended during periods of heavy training associated with adaptations in skeletal muscle. Melatonin, vitamin E and α-lipoic acid appear effective at decreasing markers of exercise-induced oxidative stress. However, evidence on their effects on endurance performance are either lacking or not supportive. Catechins, anthocyanins, coenzyme Q10 and vitamin C may improve vascular function, however, evidence is either limited to specific sub-populations and/or does not translate to improved performance. Finally, additional research should clarify the potential benefits of curcumin in improving muscle recovery post intensive exercise; and the potential hampering effects of astaxanthin, selenium and vitamin A on skeletal muscle adaptations to endurance training. Overall, we highlight the lack of supportive evidence for most antioxidant compounds to recommend to athletes.
Collapse
Affiliation(s)
- Shaun A Mason
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
| | - Adam J Trewin
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
| | - Lewan Parker
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
| | - Glenn D Wadley
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia.
| |
Collapse
|
13
|
Tremblay JC, Coombs GB, Howe CA, Vizcardo-Galindo GA, Figueroa-Mujíca RJ, Bermudez D, Tymko MM, Villafuerte FC, Ainslie PN, Pyke KE. Global Reach 2018: reduced flow-mediated dilation stimulated by sustained increases in shear stress in high-altitude excessive erythrocytosis. Am J Physiol Heart Circ Physiol 2019; 317:H991-H1001. [PMID: 31441692 DOI: 10.1152/ajpheart.00316.2019] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Excessive erythrocytosis [EE; hemoglobin concentration (Hb) ≥ 21 g/dL in adult men] is a maladaptive high-altitude pathology associated with increased cardiovascular risk and reduced reactive hyperemia flow-mediated dilation (FMD); however, whether a similar impairment occurs in response to more commonly encountered sustained increases in shear stress [sustained stimulus (SS)-FMD] over a range of overlapping stimuli is unknown. We characterized SS-FMD in response to handgrip exercise in Andeans with and without EE in Cerro de Pasco, Peru (4,330 m). Andean highlanders with EE (n = 17, Hb = 23.2 ± 1.2 g/dL) and without EE (n = 23, Hb = 18.7 ± 1.9 g/dL) performed 3 min of rhythmic handgrip exercise at 20, 35, and 50% of maximum voluntary contraction (MVC). Duplex ultrasound was used to continuously record blood velocity and diameter in the brachial artery, and blood viscosity was measured to accurately calculate shear stress. Although baseline shear stress did not differ, Andeans with EE had 22% lower shear stress than Andeans without at 50% MVC (P = 0.004). At 35 and 50% MVC, SS-FMD was 2.1 ± 2.0 and 2.8 ± 2.7% in Andeans with EE compared with 4.1 ± 3.4 and 7.5 ± 4.5% in those without (P = 0.048 and P < 0.001). The stimulus-response slope (∆shear stress vs. ∆diameter) was lower in Andeans with EE compared with Andeans without (P = 0.028). This slope was inversely related to Hb in Andeans with EE (r2 = 0.396, P = 0.007). A reduced SS-FMD in response to small muscle mass exercise in Andeans with EE indicates a generalized reduction in endothelial sensitivity to shear stress, which may contribute to increased cardiovascular risk in this population.NEW & NOTEWORTHY High-altitude excessive erythrocytosis (EE; hemoglobin concentration ≥ 21 g/dL) is a maladaptation to chronic hypoxia exposure and is associated with increased cardiovascular risk. We examined flow-mediated dilation (FMD) in response to sustained elevations in shear stress achieved using progressive handgrip exercise [sustained stimulus (SS)-FMD] in Andean highlanders with and without EE at 4,330 m. Andeans with EE demonstrated lower SS-FMD compared with those without. Heightened hemoglobin concentration was related to lower SS-FMD in Andeans with EE.
Collapse
Affiliation(s)
- Joshua C Tremblay
- Cardiovascular Stress Response Laboratory, School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
| | - Geoff B Coombs
- Centre for Heart, Lung and Vascular Health, Faculty of Health and Social Development, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
| | - Connor A Howe
- Centre for Heart, Lung and Vascular Health, Faculty of Health and Social Development, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
| | - Gustavo A Vizcardo-Galindo
- Laboratorio de Fisiología Comparada, Departamento de Ciencias Biológicas y Fisiológicas, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Rómulo J Figueroa-Mujíca
- Laboratorio de Fisiología Comparada, Departamento de Ciencias Biológicas y Fisiológicas, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Daniela Bermudez
- Laboratorio de Fisiología Comparada, Departamento de Ciencias Biológicas y Fisiológicas, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Michael M Tymko
- Centre for Heart, Lung and Vascular Health, Faculty of Health and Social Development, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
| | - Francisco C Villafuerte
- Laboratorio de Fisiología Comparada, Departamento de Ciencias Biológicas y Fisiológicas, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Philip N Ainslie
- Centre for Heart, Lung and Vascular Health, Faculty of Health and Social Development, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
| | - Kyra E Pyke
- Cardiovascular Stress Response Laboratory, School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
| |
Collapse
|
14
|
Kwon OS, Andtbacka RHI, Hyngstrom JR, Richardson RS. Vasodilatory function in human skeletal muscle feed arteries with advancing age: the role of adropin. J Physiol 2019; 597:1791-1804. [PMID: 30690728 PMCID: PMC6441888 DOI: 10.1113/jp277410] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 01/11/2019] [Indexed: 01/01/2023] Open
Abstract
KEY POINTS The present study aimed to determine the impact of ageing on endogenous adropin levels in human skeletal muscle feed arteries (SMFAs) and the role of adropin in age-related vascular dysfunction. Adropin protein expression falls progressively with advancing age in the human peripheral vasculature. Endothelial-dependent vasodilatation, typically attenuated with age, was strongly correlated with SMFA adropin protein levels. Adropin incubation restored age-related endothelial-dependent vasodilatory dysfunction and increased the phosphorylated endothelial nitric oxide synthase (eNOS)/eNOS ratio in an age-dependent manner in the SMFAs. The role of nitric oxide bioavailability was additionally indicated by NOS blockade ablating both the positive vascular effects of adropin incubation and the relationship between endothelial function and adropin protein expression. Additional evidence of a mechanistic link between declining adropin and age-related endothelial dysfunction was documented by a progressively increasing magnitude of effect of adropin-induced eNOS-mediated vasodilatation with ageing. Adropin appears to be a novel therapeutic target for facilitating the restoration of endothelial function with ageing. ABSTRACT The present study aimed to determine the impact of advancing age on endogenous adropin levels in human skeletal muscle feed arteries (SMFAs) and the role of adropin in age-related vascular dysfunction. Adropin protein expression and vasodilatory capacity was assesed in SMFAs from Young (27 ± 2 years, n = 10), Middle Aged (54 ± 2 years, n = 10) and Old (75 ± 2 years, n = 16) subjects. Endothelial-dependent vasodilatation, with and without adropin incubation, was assessed in response to flow-induced shear stress and ACh. Both SMFA adropin protein expression and endothelial-dependent vasodilatory function exhibited a progressive, age-related, reduction (Flow: Y: 65 ± 3%; Middle Aged: 36 ± 3%; Old: 15 ± 2%; ACh: Young: 63 ± 2%, Middle Aged: 34 ± 3%; Old: 23 ± 3%, P < 0.05). There was a strong positive correlation between SMFA adropin protein expression and both flow (r = 0.81, P < 0.05) and ACh (r = 0.78, P < 0.05). Adropin incubation in the Middle Aged and Old SMFAs restored the vasodilatory response to flow (Middle Aged + Adropin: 59 ± 3%; Old + Adropin: 47 ± 3%, P < 0.05) and ACh (Middle Aged + Adropin: 59 ± 3%; Old + Adropin: 49 ± 2%, P < 0.05). A mechanistic link between adropin and nitric oxide (NO) biovavailabilty was supported by (i) increased phosphorylated endothelial NO synthase (eNOS)/eNOS protein expression with adropin incubation only in the Middle Aged and Old SMFAs; (ii) eNOS blockade ablating both the positive vascular effects of adropin incubation and the relationship between endothelial function and adropin protein expression and (iii) a progressive increase in the magnitude of effect of adropin-induced eNOS-mediated vasodilatation with advancing age. Adropin could be a novel therapeutic target for facilitating the restoration of endothelial function via increased NO bioavailability, with advancing age.
Collapse
Affiliation(s)
- Oh Sung Kwon
- Department of KinesiologyUniversity of ConnecticutStorrsCTUSA
| | | | - John R. Hyngstrom
- Department of SurgeryHuntsman Cancer HospitalUniversity of UtahSalt Lake CityUTUSA
| | - Russell S. Richardson
- Geriatric Research, Education, and Clinical CenterGeorge E. Whalen VA Medical CenterSalt Lake CityUTUSA
- Department of Internal MedicineDivision of GeriatricsUniversity of UtahSalt Lake CityUTUSA
- Department of Nutrition and Integrative PhysiologyUniversity of UtahSalt Lake CityUTUSA
| |
Collapse
|
15
|
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.
Collapse
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
| |
Collapse
|
16
|
Toba H, Lindsey ML. Extracellular matrix roles in cardiorenal fibrosis: Potential therapeutic targets for CVD and CKD in the elderly. Pharmacol Ther 2019; 193:99-120. [PMID: 30149103 PMCID: PMC6309764 DOI: 10.1016/j.pharmthera.2018.08.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Whereas hypertension, diabetes, and dyslipidemia are age-related risk factors for cardiovascular disease (CVD) and chronic kidney disease (CKD), aging alone is an independent risk factor. With advancing age, the heart and kidney gradually but significantly undergo inflammation and subsequent fibrosis, which eventually results in an irreversible decline in organ physiology. Through cardiorenal network interactions, cardiac dysfunction leads to and responds to renal injury, and both facilitate aging effects. Thus, a comprehensive strategy is needed to evaluate the cardiorenal aging network. Common hallmarks shared across systems include extracellular matrix (ECM) accumulation, along with upregulation of matrix metalloproteinases (MMPs) including MMP-9. The wide range of MMP-9 substrates, including ECM components and inflammatory cytokines, implicates MMP-9 in a variety of pathological and age-related processes. In particular, there is strong evidence that inflammatory cell-derived MMP-9 exacerbates cardiorenal aging. This review explores the potential therapeutic targets against CVD and CKD in the elderly, focusing on ECM and MMP roles.
Collapse
Affiliation(s)
- Hiroe Toba
- Department of Clinical Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, Kyoto, Japan.
| | - Merry L Lindsey
- Mississippi Center for Heart Research, Department of Physiology and Biophysics, University of Mississippi Medical Center, and Research Service, G.V. (Sonny) Montgomery Veterans Affairs Medical Center, Jackson, MS, USA.
| |
Collapse
|
17
|
McPhee IAC, Pyke KE. Thirty minutes of handgrip exercise potentiates flow-mediated dilatation in response to sustained and transient shear stress stimuli to a similar extent. Exp Physiol 2018; 103:1326-1337. [DOI: 10.1113/ep087065] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 07/27/2018] [Indexed: 12/26/2022]
Affiliation(s)
- I. A. C. McPhee
- Cardiovascular Stress Response Laboratory, School of Kinesiology and Health Studies; Queen's University; Kingston Ontario Canada
| | - K. E. Pyke
- Cardiovascular Stress Response Laboratory, School of Kinesiology and Health Studies; Queen's University; Kingston Ontario Canada
| |
Collapse
|
18
|
Barbosa TC, Kaur J, Stephens BY, Akins JD, Keller DM, Brothers RM, Fadel PJ. Attenuated forearm vascular conductance responses to rhythmic handgrip in young African-American compared with Caucasian-American men. Am J Physiol Heart Circ Physiol 2018; 315:H1316-H1321. [PMID: 30118345 DOI: 10.1152/ajpheart.00387.2018] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Previous studies have demonstrated that African-American (AA) individuals have heightened vasoconstrictor and reduced vasodilator responses under resting conditions compared with Caucasian-American (CA) individuals. However, potential differences in vascular responses to exercise remain unclear. Therefore, we tested the hypothesis that, compared with CA subjects, AA subjects would present an attenuated increase in forearm vascular conductance (FVC) during rhythmic handgrip exercise. Forearm blood flow (FBF; duplex Doppler ultrasound) and mean arterial pressure (MAP; finger photoplethysmography) were measured in healthy young CA ( n = 10) and AA ( n = 10) men during six trials of rhythmic handgrip performed at workloads of 4, 8, 12, 16, 20, and 24 kg. FVC (calculated as FBF/MAP), FBF, and MAP were similar between groups at rest (FVC: 63 ± 7 ml·min-1·100 mmHg-1 in CA subjects vs. 62 ± 7 ml·min-1·100 mmHg-1 in AA subjects, P = 0.862). There was an intensity-dependent increase in FVC during exercise in both groups; however, AA subjects presented lower FVC (interaction P < 0.001) at 8-, 12-, 16-, 20-, and 24-kg workloads (e.g., 24 kg: 324 ± 20 ml·min-1·100 mmHg-1 in CA subjects vs. 241 ± 21 ml·min-1·100 mmHg-1 in AA subjects, P < 0.001). FBF responses to exercise were also lower in AA subjects (interaction P < 0.001), whereas MAP responses did not differ between groups (e.g., ∆MAP at 24 kg: +19 ± 2 mmHg in CA subjects vs. +19 ± 2 mmHg in AA subjects, interaction P = 0.950). These findings indicate lower hyperemic responses to rhythmic handgrip exercise in AA men compared with CA men. NEW & NOTEWORTHY It is known that African-American individuals have heightened vasoconstriction and reduced vasodilation under resting conditions compared with Caucasian-American individuals. Here, we identified that the hyperemic response to moderate and high-intensity rhythmic handgrip exercise was lower in healthy young African-American men.
Collapse
Affiliation(s)
- Thales C Barbosa
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington , Arlington, Texas
| | - Jasdeep Kaur
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington , Arlington, Texas
| | - Brandi Y Stephens
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington , Arlington, Texas
| | - John D Akins
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington , Arlington, Texas
| | - David M Keller
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington , Arlington, Texas
| | - R Matthew Brothers
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington , Arlington, Texas
| | - Paul J Fadel
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington , Arlington, Texas
| |
Collapse
|
19
|
Scalzo RL, Bauer TA, Harrall K, Moreau K, Ozemek C, Herlache L, McMillin S, Huebschmann AG, Dorosz J, Reusch JEB, Regensteiner JG. Acute vitamin C improves cardiac function, not exercise capacity, in adults with type 2 diabetes. Diabetol Metab Syndr 2018; 10:7. [PMID: 29456629 PMCID: PMC5813393 DOI: 10.1186/s13098-018-0306-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Accepted: 01/04/2018] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND People with type 2 diabetes (T2D) have impaired exercise capacity, even in the absence of complications, which is predictive of their increased cardiovascular mortality. Cardiovascular dysfunction is one potential cause of this exercise defect. Acute infusion of vitamin C has been separately shown to improve diastolic and endothelial function in prior studies. We hypothesized that acute vitamin C infusion would improve exercise capacity and that these improvements would be associated with improved cardiovascular function. METHODS Adults with T2D (n = 31, 7 female, 24 male, body mass index (BMI): 31.5 ± 0.8 kg/m2) and BMI-similar healthy adults (n = 21, 11 female, 10 male, BMI: 30.4 ± 0.7 kg/m2) completed two randomly ordered visits: IV infusion of vitamin C (7.5 g) and a volume-matched saline infusion. During each visit peak oxygen uptake (VO2peak), brachial artery flow mediated dilation (FMD), reactive hyperemia (RH; plethysmography), and cardiac echocardiography were measured. General linear mixed models were utilized to assess the differences in all study variables. RESULTS Acute vitamin C infusion improved diastolic function, assessed by lateral and septal E:E' (P < 0.01), but did not change RH (P = 0.92), or VO2peak (P = 0.33) in any participants. CONCLUSION Acute vitamin C infusion improved diastolic function but did not change FMD, forearm reactive hyperemia, or peak exercise capacity. Future studies should further clarify the role of endothelial function as well as other possible physiological causes of exercise impairment in order to provide potential therapeutic targets.Trial registration NCT00786019. Prospectively registered May 2008.
Collapse
Affiliation(s)
- Rebecca L. Scalzo
- Division of Endocrinology, Department of Medicine, University of Colorado School of Medicine (UCSOM), 12801 E17th Ave, Aurora, CO 80045 USA
- Department of Medicine, Center for Women’s Health Research, University of Colorado School of Medicine (UCSOM), Aurora, CO USA
| | - Timothy A. Bauer
- Division of General Internal Medicine, Department of Medicine, University of Colorado School of Medicine (UCSOM), Aurora, CO USA
| | - Kylie Harrall
- Department of Medicine, Center for Women’s Health Research, University of Colorado School of Medicine (UCSOM), Aurora, CO USA
| | - Kerrie Moreau
- Division of Geriatrics, Department of Medicine, University of Colorado School of Medicine (UCSOM), Aurora, CO USA
- Department of Medicine, Center for Women’s Health Research, University of Colorado School of Medicine (UCSOM), Aurora, CO USA
- VAMC-Geriatric Research Education and Clinical Center (GRECC), Denver, CO 80215 USA
| | - Cemal Ozemek
- Division of Geriatrics, Department of Medicine, University of Colorado School of Medicine (UCSOM), Aurora, CO USA
| | - Leah Herlache
- Division of General Internal Medicine, Department of Medicine, University of Colorado School of Medicine (UCSOM), Aurora, CO USA
| | - Shawna McMillin
- Division of General Internal Medicine, Department of Medicine, University of Colorado School of Medicine (UCSOM), Aurora, CO USA
| | - Amy G. Huebschmann
- Division of General Internal Medicine, Department of Medicine, University of Colorado School of Medicine (UCSOM), Aurora, CO USA
- Department of Medicine, Center for Women’s Health Research, University of Colorado School of Medicine (UCSOM), Aurora, CO USA
| | - Jennifer Dorosz
- Division of Cardiology, Department of Medicine, University of Colorado School of Medicine (UCSOM), Aurora, CO USA
| | - Jane E. B. Reusch
- Division of Endocrinology, Department of Medicine, University of Colorado School of Medicine (UCSOM), 12801 E17th Ave, Aurora, CO 80045 USA
- Department of Medicine, Center for Women’s Health Research, University of Colorado School of Medicine (UCSOM), Aurora, CO USA
- Veterans Administration Medical Center (VAMC), Denver, CO 80215 USA
| | - Judith G. Regensteiner
- Division of General Internal Medicine, Department of Medicine, University of Colorado School of Medicine (UCSOM), Aurora, CO USA
- Department of Medicine, Center for Women’s Health Research, University of Colorado School of Medicine (UCSOM), Aurora, CO USA
| |
Collapse
|
20
|
Tremblay JC, Pyke KE. Flow-mediated dilation stimulated by sustained increases in shear stress: a useful tool for assessing endothelial function in humans? Am J Physiol Heart Circ Physiol 2017; 314:H508-H520. [PMID: 29167121 DOI: 10.1152/ajpheart.00534.2017] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Investigations of human conduit artery endothelial function via flow-mediated vasodilation (FMD) have largely been restricted to the reactive hyperemia (RH) technique, wherein a transient increase in shear stress after the release of limb occlusion stimulates upstream conduit artery vasodilation (RH-FMD). FMD can also be assessed in response to sustained increases in shear stress [sustained stimulus (SS)-FMD], most often created with limb heating or exercise. Exercise in particular creates a physiologically relevant stimulus because shear stress increases, and FMD occurs, during typical day-to-day activity. Several studies have identified that various conditions and acute interventions have a disparate impact on RH-FMD versus SS-FMD, sometimes with only the latter demonstrating impairment. Indeed, evidence suggests that transient (RH) and sustained (SS) shear stress stimuli may be transduced via different signaling pathways, and, as such, SS-FMD and RH-FMD appear to offer unique insights regarding endothelial function. The present review describes the techniques used to assess SS-FMD and summarizes the evidence regarding 1) SS-FMD as an index of endothelial function in humans, highlighting comparisons with RH-FMD, and 2) potential differences in shear stress transduction and vasodilator production stimulated by transient versus sustained shear stress stimuli. The evidence suggests that SS-FMD is a useful tool to assess endothelial function and that further research is required to characterize the mechanisms involved and its association with long-term cardiovascular outcomes. NEW & NOTEWORTHY Sustained increases in peripheral conduit artery shear stress, created via distal skin heating or exercise, provide a physiologically relevant stimulus for flow-mediated dilation (FMD). Sustained stimulus FMD and FMD stimulated by transient, reactive hyperemia-induced increases in shear stress provide distinct assessments of conduit artery endothelial function.
Collapse
Affiliation(s)
- Joshua C Tremblay
- Cardiovascular Stress Response Laboratory, School of Kinesiology and Health Studies, Queen's University , Kingston, Ontario , Canada
| | - Kyra E Pyke
- Cardiovascular Stress Response Laboratory, School of Kinesiology and Health Studies, Queen's University , Kingston, Ontario , Canada
| |
Collapse
|
21
|
Romero SA, Gagnon D, Adams AN, Moralez G, Kouda K, Jaffery MF, Cramer MN, Crandall CG. Folic acid ingestion improves skeletal muscle blood flow during graded handgrip and plantar flexion exercise in aged humans. Am J Physiol Heart Circ Physiol 2017; 313:H658-H666. [PMID: 28667051 DOI: 10.1152/ajpheart.00234.2017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 06/16/2017] [Accepted: 06/28/2017] [Indexed: 12/12/2022]
Abstract
Skeletal muscle blood flow is attenuated in aged humans performing dynamic exercise, which is due, in part, to impaired local vasodilatory mechanisms. Recent evidence suggests that folic acid improves cutaneous vasodilation during localized and whole body heating through nitric oxide-dependent mechanisms. However, it is unclear whether folic acid improves vasodilation in other vascular beds during conditions of increased metabolism (i.e., exercise). The purpose of this study was to test the hypothesis that folic acid ingestion improves skeletal muscle blood flow in aged adults performing graded handgrip and plantar flexion exercise via increased vascular conductance. Nine healthy, aged adults (two men and seven women; age: 68 ± 5 yr) performed graded handgrip and plantar flexion exercise before (control), 2 h after (acute, 5 mg), and after 6 wk (chronic, 5 mg/day) folic acid ingestion. Forearm (brachial artery) and leg (superficial femoral artery) blood velocity and diameter were measured via Duplex ultrasonography and used to calculate blood flow. Acute and chronic folic acid ingestion increased serum folate (both P < 0.05 vs. control). During handgrip exercise, acute and chronic folic acid ingestion increased forearm blood flow (both conditions P < 0.05 vs. control) and vascular conductance (both P < 0.05 vs. control). During plantar flexion exercise, acute and chronic folic acid ingestion increased leg blood flow (both P < 0.05 vs. control), but only acute folic acid ingestion increased vascular conductance (P < 0.05 vs. control). Taken together, folic acid ingestion increases blood flow to active skeletal muscle primarily via improved local vasodilation in aged adults.NEW & NOTEWORTHY Our findings demonstrate that folic acid ingestion improves blood flow via enhanced vascular conductance in the exercising skeletal muscle of aged humans. These findings provide evidence for the therapeutic use of folic acid to improve skeletal muscle blood flow, and perhaps exercise and functional capacity, in human primary aging.Listen to this article's corresponding podcast at http://ajpheart.podbean.com/e/folic-acid-and-exercise-hyperemia-in-aging/.
Collapse
Affiliation(s)
- Steven A Romero
- University of Texas Southwestern Medical Center and Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, Texas
| | - Daniel Gagnon
- Montreal Heart Institute, Université de Montréal, Montréal, Quebec, Canada.,Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Montréal, Quebec, Canada; and
| | - Amy N Adams
- University of Texas Southwestern Medical Center and Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, Texas
| | - Gilbert Moralez
- University of Texas Southwestern Medical Center and Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, Texas
| | - Ken Kouda
- Wakayama Medical University, Wakayama, Japan
| | - Manall F Jaffery
- University of Texas Southwestern Medical Center and Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, Texas
| | - Matthew N Cramer
- University of Texas Southwestern Medical Center and Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, Texas
| | - Craig G Crandall
- University of Texas Southwestern Medical Center and Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, Texas;
| |
Collapse
|
22
|
Machin DR, Clifton HL, Garten RS, Gifford JR, Richardson RS, Wray DW, Frech TM, Donato AJ. Exercise-induced brachial artery blood flow and vascular function is impaired in systemic sclerosis. Am J Physiol Heart Circ Physiol 2016; 311:H1375-H1381. [PMID: 27694218 DOI: 10.1152/ajpheart.00547.2016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 09/26/2016] [Indexed: 11/22/2022]
Abstract
Systemic sclerosis (SSc) is a rare autoimmune disease characterized by debilitating fibrosis and vascular dysfunction; however, little is known about the circulatory response to exercise in this population. Therefore, we examined the peripheral hemodynamic and vasodilatory responses to handgrip exercise in 10 patients with SSc (61 ± 4 yr) and 15 age-matched healthy controls (56 ± 5 yr). Brachial artery diameter, blood flow, and mean arterial pressure (MAP) were determined at rest and during progressive static-intermittent handgrip exercise. Patients with SSc and controls were similar in body stature, handgrip strength, and MAP; however, brachial artery blood flow at rest was nearly twofold lower in patients with SSc compared with controls (22 ± 4 vs. 42 ± 5 ml/min, respectively; P < 0.05). Additionally, SSc patients had an ∼18% smaller brachial artery lumen diameter with an ∼28% thicker arterial wall at rest (P < 0.05). Although, during handgrip exercise, there were no differences in MAP between the groups, exercise-induced hyperemia and therefore vascular conductance were ∼35% lower at all exercise workloads in patients with SSc (P < 0.05). Brachial artery vasodilation, as assessed by the relationship between Δbrachial artery diameter and Δshear rate, was significantly attenuated in the patients with SSc (P < 0.05). Finally, vascular dysfunction in the patients with SSc was accompanied by elevated blood markers of oxidative stress and attenuated endogenous antioxidant activity (P < 0.05). Together, these findings reveal attenuated exercise-induced brachial artery blood flow and conduit arterial vasodilatory dysfunction during handgrip exercise in SSc and suggest that elevated oxidative stress may play a role.
Collapse
Affiliation(s)
- Daniel R Machin
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - Heather L Clifton
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - Ryan S Garten
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah.,Department of Kinesiology and Health Sciences, Virginia Commonwealth University, Richmond, Virginia
| | - Jayson R Gifford
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - Russell S Richardson
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah.,Veterans Affairs Salt Lake City, GRECC, Salt Lake City, Utah; and
| | - D Walter Wray
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah.,Veterans Affairs Salt Lake City, GRECC, Salt Lake City, Utah; and
| | - Tracy M Frech
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - Anthony J Donato
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah; .,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah.,Department of Biochemistry, University of Utah, Salt Lake City, Utah.,Veterans Affairs Salt Lake City, GRECC, Salt Lake City, Utah; and
| |
Collapse
|