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Belbis MD, Yap Z, Hobart SE, Ferguson SK, Hirai DM. Effects of acute phosphodiesterase type 5 inhibition on skeletal muscle interstitial PO 2 during contractions and recovery. Nitric Oxide 2024; 142:16-25. [PMID: 37979932 DOI: 10.1016/j.niox.2023.11.004] [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: 07/10/2023] [Revised: 10/26/2023] [Accepted: 11/14/2023] [Indexed: 11/20/2023]
Abstract
The oxygen partial pressure within the interstitial space (PO2is; mmHg) provides the driving force for oxygen diffusion into the myocyte thereby supporting oxidative phosphorylation. We tested the hypothesis that potentiation of the nitric oxide pathway with sildenafil (phosphodiesterase type 5 inhibitor) would enhance PO2is during muscle metabolic transitions, thereby slowing PO2is on- and accelerating PO2is off-kinetics. The rat spinotrapezius muscle (n = 17) was exposed for PO2is measurements via phosphorescence quenching under control (CON), low-dose sildenafil (1 mg/kg i.a., SIL1) and high-dose sildenafil (7 mg/kg i.a., SIL7). Data were collected at rest and during submaximal twitch contractions (1 Hz, 4-6 V, 3 min) and recovery (3 min). Mean arterial blood pressure (MAP; mmHg) was reduced with both SIL1 (pre:132 ± 5; post:99 ± 5) and SIL7 (pre:111 ± 6; post:99 ± 4) (p < 0.05). SIL7 elevated resting PO2is (18.4 ± 1.1) relative to both CON (15.7 ± 0.7) and SIL1 (15.2 ± 0.7) (p < 0.05). In addition, SIL7 increased end-recovery PO2is (17.7 ± 1.6) compared to CON (12.8 ± 0.9) and SIL1 (13.4 ± 0.8) (p < 0.05). The overall PO2is response during recovery (i.e., area under the PO2is curve) was greater in SIL7 (4107 ± 444) compared to CON (3493 ± 222) and SIL1 (3114 ± 205 mmHg s) (p < 0.05). Contrary to our hypothesis, there was no impact of acute SIL (1 or 7 mg/kg) on the speed of the PO2is response during contractions or recovery (p > 0.05). However, sildenafil lowered MAP and improved skeletal muscle interstitial oxygenation in healthy rats. Specifically, SIL7 enhanced PO2is at rest and during recovery from submaximal muscle contractions. Potentiation of the nitric oxide pathway with sildenafil enhances microvascular blood-myocyte O2 transport and is expected to improve repeated bouts of contractile activity.
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Affiliation(s)
- Michael D Belbis
- Department of Health and Kinesiology, Purdue University, West Lafayette, IN, USA; Department of Exercise Science, Aurora University, Aurora, IL, USA
| | - Zhen Yap
- Department of Health and Kinesiology, Purdue University, West Lafayette, IN, USA
| | - Sara E Hobart
- Department of Health and Kinesiology, Purdue University, West Lafayette, IN, USA
| | - Scott K Ferguson
- Department of Human Factors and Behavioral Neurobiology, Embry-Riddle Aeronautical University, Daytona Beach, FL, USA
| | - Daniel M Hirai
- Department of Health and Kinesiology, Purdue University, West Lafayette, IN, USA.
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Hughes WE, Kruse NT, Ueda K, Feider AJ, Hanada S, Bock JM, Casey DP. Dietary nitrate does not acutely enhance skeletal muscle blood flow and vasodilation in the lower limbs of older adults during single-limb exercise. Eur J Appl Physiol 2020; 120:1357-1369. [DOI: 10.1007/s00421-020-04368-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 04/05/2020] [Indexed: 12/21/2022]
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Cavalcante AKM, Siqueira RCL, Feitosa Júnior VN, de Andrade CR, Santos AA, Silva MTB. Acute exercise inhibits gastric emptying of liquids in rats: influence of the NO-cGMP pathway. ACTA ACUST UNITED AC 2018; 51:e7541. [PMID: 30304131 PMCID: PMC6172930 DOI: 10.1590/1414-431x20187541] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 08/03/2018] [Indexed: 01/22/2023]
Abstract
We previously found that acute exercise inhibited the gastric emptying of liquid in awake rats by causing an acid-base imbalance. In the present study, we investigated the involvement of the nitric oxide-cyclic guanosine monophosphate (NO-cGMP) pathway, vasoactive intestinal peptide (VIP), and corticotropin-releasing factor (CRF) peptide in this phenomenon. Male rats were divided into exercise or sedentary group and were subjected to a 15-min swim session against a load (2.5 or 5% b.w.). The rate of gastric emptying was evaluated after 5, 10, or 20 min postprandially. Separate groups of rats were treated with vehicle (0.9% NaCl, 0.1 mL/100 g, ip) or one of the following agents: atropine (1.0 mg/kg, ip), the NO non-selective inhibitor Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME; 10.0 mg/kg, ip), or the selective cGMP inhibitor 1H-(1,2,4)oxadiazole[4,3-a]quinoxalin-1-one (ODQ; 5.0 mg/kg, ip), the i-NOS non-specific inhibitor (aminoguanidine; 10.0 mg/kg, ip), the corticotropin-releasing factor receptor antagonist (astressin; 100 µg/kg, ip), or the vasoactive intestinal peptide (VIP) receptor antagonist Lys1, Pro2,5, Arg3,4, Tyr6 (100 µg/kg, ip). Compared to sedentary rats, both the 2.5 and 5% exercise groups exhibited higher (P<0.05) values of blood lactate and fractional gastric dye recovery. Corticosterone and NO levels increased (P<0.05) in the 5% exercised rats. Pretreatment with astressin, VIP antagonist, atropine, L-NAME, and ODQ prevented the increase in gastric retention caused by exercise in rats. Acute exercise increased gastric retention, a phenomenon that appears to be mediated by the NO-cGMP pathway, CRF, and VIP receptors.
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Affiliation(s)
- A K M Cavalcante
- Programa de Pós-Graduação em Ciências Biológicas/Biotecnologia, Centro Universitário UNINTA, Sobral, CE, Brasil.,Programa de Pós-Graduação em Ciências Médicas, Universidade Federal do Ceará, Fortaleza, CE, Brasil
| | - R C L Siqueira
- Departmento de Fisiologia e Farmacologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE, Brasil
| | - V N Feitosa Júnior
- Departmento de Fisiologia e Farmacologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE, Brasil
| | - C R de Andrade
- Laboratorio de Pesquisa Translacional, Centro Universitário Christus (UniChristus), Fortaleza, CE, Brasil
| | - A A Santos
- Programa de Pós-Graduação em Ciências Médicas, Universidade Federal do Ceará, Fortaleza, CE, Brasil.,Departmento de Fisiologia e Farmacologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE, Brasil
| | - M T B Silva
- Departmento de Educação Física, Universidade Federal do Piauí, Teresina, PI, Brasil
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Kellawan JM, Limberg JK, Scruggs ZM, Nicholson WT, Schrage WG, Joyner MJ, Curry TB. Phosphodiesterase-5 inhibition preserves exercise-onset vasodilator kinetics when NOS activity is reduced. J Appl Physiol (1985) 2017; 124:276-282. [PMID: 28982942 DOI: 10.1152/japplphysiol.00483.2017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Nitric oxide (NO)-mediated vasodilation contributes to the rapid rise in muscle blood flow at exercise onset. This occurs via increased cyclic guanosine monophosphate (cGMP), which is catabolized by phosphodiesterase-5 (PDE-5). Whether PDE-5 limits exercise vasodilation onset kinetics is unknown. We hypothesized the time course of exercise vasodilation would be 1) accelerated during PDE-5 inhibition (sildenafil citrate, SDF) and 2) decelerated during NO synthase inhibition ( NG-monomethyl-l-arginine, l-NMMA), and 3) the effect of SDF on vasodilation onset kinetics would be attenuated with concurrent l-NMMA. Data from 29 healthy adults were analyzed. Individuals completed 5 min of moderate-intensity forearm exercise under control conditions and during 1) oral SDF ( n = 8), 2) intra-arterial l-NMMA ( n = 15), or 3) combined SDF + l-NMMA ( n = 6). Forearm blood flow (FBF; Doppler ultrasound of the brachial artery) and mean brachial artery blood pressure (MAP) were measured continuously. Forearm vascular conductance (FVC, FBF ÷ MAP) was curve-fit with a monoexponential model, and vasodilation onset kinetics were assessed by mean response time (MRT, time to achieve 63% of steady state). SDF had no effect on MRT ( P = 0.90). NOS inhibition increased MRT ( P = 0.01). MRT during SDF+l-NMMA was not different from control exercise ( P = 0.76). PDE-5 inhibition alone has no effect on rapid-onset vasodilation. Whereas NOS inhibition decelerates vasodilator kinetics, when combined with SDF, vasodilator kinetics do not differ from control. These data suggest NO-independent activation of cGMP occurs at exercise onset; thus PDE-5 inhibition may improve vasodilation in pathologies where NO bioavailability is impaired. NEW & NOTEWORTHY We show that when NO bioavailability is reduced, PDE-5 inhibition can restore vasodilation onset kinetics of exercise-mediated vasodilation via NO-independent cGMP pathways. These data suggest PDE-5 inhibition may improve exercise vasodilation onset kinetics in pathologies where NO bioavailability is impaired.
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Affiliation(s)
- J Mikhail Kellawan
- Department of Kinesiology, University of Wisconsin , Madison, Wisconsin.,Department of Health and Exercise Science, University of Oklahoma , Norman, Oklahoma
| | - Jacqueline K Limberg
- Department of Anesthesiology, Mayo Clinic College of Medicine , Rochester, Minnesota
| | - Zachariah M Scruggs
- Department of Anesthesiology, Mayo Clinic College of Medicine , Rochester, Minnesota
| | - Wayne T Nicholson
- Department of Anesthesiology, Mayo Clinic College of Medicine , Rochester, Minnesota
| | - William G Schrage
- Department of Kinesiology, University of Wisconsin , Madison, Wisconsin.,Department of Anesthesiology, Mayo Clinic College of Medicine , Rochester, Minnesota
| | - Michael J Joyner
- Department of Anesthesiology, Mayo Clinic College of Medicine , Rochester, Minnesota
| | - Timothy B Curry
- Department of Anesthesiology, Mayo Clinic College of Medicine , Rochester, Minnesota
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Piil P, Smith Jørgensen T, Egelund J, Damsgaard R, Gliemann L, Hellsten Y, Nyberg M. Exercise training improves blood flow to contracting skeletal muscle of older men via enhanced cGMP signaling. J Appl Physiol (1985) 2017; 124:109-117. [PMID: 28982945 DOI: 10.1152/japplphysiol.00634.2017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Physical activity has the potential to offset age-related impairments in the regulation of blood flow and O2 delivery to the exercising muscles; however, the mechanisms underlying this effect of physical activity remain poorly understood. The present study examined the role of cGMP in training-induced adaptations in the regulation of skeletal muscle blood flow and oxidative metabolism during exercise in aging humans. We measured leg hemodynamics and oxidative metabolism during exercise engaging the knee extensor muscles in young [ n = 15, 25 ± 1 (SE) yr] and older ( n = 15, 72 ± 1 yr) subjects before and after a period of aerobic high-intensity exercise training. To determine the role of cGMP signaling, pharmacological inhibition of phosphodiesterase 5 (PDE5) was performed. Before training, inhibition of PDE5 increased ( P < 0.05) skeletal muscle blood flow and O2 uptake during moderate-intensity exercise in the older group; however, these effects of PDE5 inhibition were not detected after training. These findings suggest a role for enhanced cGMP signaling in the training-induced improvement of regulation of blood flow in contracting skeletal muscle of older men. NEW & NOTEWORTHY The present study provides evidence for enhanced cyclic GMP signaling playing an essential role in the improved regulation of blood flow in contracting skeletal muscle of older men with aerobic exercise training.
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Affiliation(s)
- Peter Piil
- Department of Nutrition, Exercise and Sports, University of Copenhagen , Copenhagen , Denmark
| | - Tue Smith Jørgensen
- Department of Nutrition, Exercise and Sports, University of Copenhagen , Copenhagen , Denmark.,Department of Orthopedics, Herlev and Gentofte Hospital, Copenhagen, Denmark
| | - Jon Egelund
- Department of Nutrition, Exercise and Sports, University of Copenhagen , Copenhagen , Denmark
| | - Rasmus Damsgaard
- Department of Nutrition, Exercise and Sports, University of Copenhagen , Copenhagen , Denmark
| | - Lasse Gliemann
- Department of Nutrition, Exercise and Sports, University of Copenhagen , Copenhagen , Denmark
| | - Ylva Hellsten
- Department of Nutrition, Exercise and Sports, University of Copenhagen , Copenhagen , Denmark
| | - Michael Nyberg
- Department of Nutrition, Exercise and Sports, University of Copenhagen , Copenhagen , Denmark
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