1
|
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.
Collapse
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.
| |
Collapse
|
2
|
Samidurai A, Xi L, Das A, Kukreja RC. Beyond Erectile Dysfunction: cGMP-Specific Phosphodiesterase 5 Inhibitors for Other Clinical Disorders. Annu Rev Pharmacol Toxicol 2023; 63:585-615. [PMID: 36206989 DOI: 10.1146/annurev-pharmtox-040122-034745] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Cyclic guanosine monophosphate (cGMP), an important intracellular second messenger, mediates cellular functional responses in all vital organs. Phosphodiesterase 5 (PDE5) is one of the 11 members of the cyclic nucleotide phosphodiesterase (PDE) family that specifically targets cGMP generated by nitric oxide-driven activation of the soluble guanylyl cyclase. PDE5 inhibitors, including sildenafil and tadalafil, are widely used for the treatment of erectile dysfunction, pulmonary arterial hypertension, and certain urological disorders. Preclinical studies have shown promising effects of PDE5 inhibitors in the treatment of myocardial infarction, cardiac hypertrophy, heart failure, cancer and anticancer-drug-associated cardiotoxicity, diabetes, Duchenne muscular dystrophy, Alzheimer's disease, and other aging-related conditions. Many clinical trials with PDE5 inhibitors have focused on the potential cardiovascular, anticancer, and neurological benefits. In this review, we provide an overview of the current state of knowledge on PDE5 inhibitors and their potential therapeutic indications for various clinical disorders beyond erectile dysfunction.
Collapse
Affiliation(s)
- Arun Samidurai
- Division of Cardiology, Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia, USA;
| | - Lei Xi
- Division of Cardiology, Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia, USA;
| | - Anindita Das
- Division of Cardiology, Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia, USA;
| | - Rakesh C Kukreja
- Division of Cardiology, Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia, USA;
| |
Collapse
|
3
|
Nyberg M, Jones AM. Matching of O2 Utilization and O2 Delivery in Contracting Skeletal Muscle in Health, Aging, and Heart Failure. Front Physiol 2022; 13:898395. [PMID: 35774284 PMCID: PMC9237395 DOI: 10.3389/fphys.2022.898395] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 05/05/2022] [Indexed: 12/12/2022] Open
Abstract
Skeletal muscle is one of the most dynamic metabolic organs as evidenced by increases in metabolic rate of >150-fold from rest to maximal contractile activity. Because of limited intracellular stores of ATP, activation of metabolic pathways is required to maintain the necessary rates of ATP re-synthesis during sustained contractions. During the very early phase, phosphocreatine hydrolysis and anaerobic glycolysis prevails but as activity extends beyond ∼1 min, oxidative phosphorylation becomes the major ATP-generating pathway. Oxidative metabolism of macronutrients is highly dependent on the cardiovascular system to deliver O2 to the contracting muscle fibres, which is ensured through a tight coupling between skeletal muscle O2 utilization and O2 delivery. However, to what extent O2 delivery is ideal in terms of enabling optimal metabolic and contractile function is context-dependent and determined by a complex interaction of several regulatory systems. The first part of the review focuses on local and systemic mechanisms involved in the regulation of O2 delivery and how integration of these influences the matching of skeletal muscle O2 demand and O2 delivery. In the second part, alterations in cardiovascular function and structure associated with aging and heart failure, and how these impact metabolic and contractile function, will be addressed. Where applicable, the potential of exercise training to offset/reverse age- and disease-related cardiovascular declines will be highlighted in the context of skeletal muscle metabolic function. The review focuses on human data but also covers animal observations.
Collapse
Affiliation(s)
- Michael Nyberg
- Vascular Biology, Global Drug Discovery, Novo Nordisk A/S, Maaloev, Denmark
- *Correspondence: Michael Nyberg,
| | - Andrew M. Jones
- Department of Sport and Health Sciences, University of Exeter, Exeter, United Kingdom
| |
Collapse
|
4
|
Hearon CM, Richards JC, Racine ML, Luckasen GJ, Larson DG, Dinenno FA. Augmentation of endothelium-dependent vasodilatory signalling improves functional sympatholysis in contracting muscle of older adults. J Physiol 2020; 598:2323-2336. [PMID: 32306393 DOI: 10.1113/jp279462] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 04/14/2020] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS The ability of contracting skeletal muscle to attenuate sympathetic vasoconstriction (functional sympatholysis) is critical for maintaining blood flow during exercise-mediated sympathoexcitation. Functional sympatholysis and endothelial function are impaired with ageing, resulting in compromised blood flow and oxygen delivery to contracting skeletal muscle during exercise. In the present study, intra-arterial infusion of ACh or ATP to augment endothelium-dependent signalling during exercise attenuated α1 -adrenergic vasoconstriction in the contracting muscle of older adults. The vascular signalling mechanisms capable of functional sympatholysis are preserved in healthy ageing, and thus the age-related impairment in functional sympatholysis probably results from the loss of a functional signal (e.g. plasma [ATP]) as opposed to an intrinsic endothelial dysfunction. ABSTRACT The ability of contracting skeletal muscle to attenuate sympathetic α-adrenergic vasoconstriction ('functional sympatholysis') is impaired with age. In young adults, increasing endothelium-dependent vasodilatory signalling during mild exercise augments sympatholysis. In the present study, we tested the hypothesis that increasing endothelium-dependent signalling during exercise in older adults can improve sympatholysis. In 16 older individuals (Protocol 1, n = 8; Protocol 2, n = 8), we measured forearm blood flow (Doppler ultrasound) and calculated changes in vascular conductance (FVC) to local intra-arterial infusion of phenylephrine (PE; α1 -agonist) during (i) infusion of an endothelium-dependent vasodilator alone (Protocol 1: ACh or Protocol 2: low dose ATP); (ii) mild handgrip exercise (5% maximum voluntary contraction; MVC); (iii) moderate handgrip exercise (15% MVC); and (iv) mild or moderate handgrip exercise + infusion of ACh or ATP to augment endothelium-dependent signalling. PE caused robust vasoconstriction in resting skeletal muscle during control vasodilator infusions (ΔFVC: ACh: -31 ± 3 and ATP: -30 ± 4%). PE-mediated vasoconstriction was not attenuated by mild or moderate intensity exercise (ΔFVC: 5% MVC: -30 ± 9; 15% MVC: -33 ± 8%; P > 0.05 vs. control ACh and ATP), indicative of impaired sympatholysis, and ACh or ATP infusion during mild exercise did not impact this response. However, augmentation of endothelium-dependent signalling via infusion of ACh or ATP during moderate intensity exercise attenuated PE-mediated vasoconstriction (ΔFVC: -13 ± 1 and -19 ± 5%, respectively; P < 0.05 vs. all conditions). Our findings demonstrate that, given a sufficient stimulus, endothelium-dependent sympatholysis remains intact in older adults. Strategies aimed at activating such pathways represent a viable approach for improving sympatholysis and thus tissue blood flow and oxygen delivery in older adults.
Collapse
Affiliation(s)
- Christopher M Hearon
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
| | - Jennifer C Richards
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
| | - Mathew L Racine
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
| | - Gary J Luckasen
- Medical Center of the Rockies Foundation, University of Colorado Health System, Loveland, CO, USA
| | - Dennis G Larson
- Medical Center of the Rockies Foundation, University of Colorado Health System, Loveland, CO, USA
| | - Frank A Dinenno
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA.,Center for Cardiovascular Research, Colorado State University, Fort Collins, CO, USA
| |
Collapse
|
5
|
Ölmestig J, Marlet IR, Hansen RH, Rehman S, Krawcyk RS, Rostrup E, Lambertsen KL, Kruuse C. Tadalafil may improve cerebral perfusion in small-vessel occlusion stroke-a pilot study. Brain Commun 2020; 2:fcaa020. [PMID: 33033800 PMCID: PMC7530832 DOI: 10.1093/braincomms/fcaa020] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 12/22/2019] [Accepted: 12/28/2019] [Indexed: 01/29/2023] Open
Abstract
New treatments for cerebral small-vessel disease are needed to reduce the risk of small-vessel occlusion stroke and vascular cognitive impairment. We investigated an approach targeted to the signalling molecule cyclic guanosine monophosphate, using the phosphodiesterase 5 inhibitor tadalafil, to explore if it improves cerebral blood flow and endothelial function in patients with cerebral small-vessel disease and stroke. In a randomized, double-blinded, placebo-controlled, cross-over pilot trial (NCT02801032), we included patients who had a previous (>6 months) small-vessel occlusion stroke. They received a single dose of either 20 mg tadalafil or placebo on 2 separate days at least 1 week apart. We measured the following: baseline MRI for lesion load, repeated measurements of blood flow velocity in the middle cerebral artery by transcranial Doppler, blood oxygen saturation in the cortical microvasculature by near-infrared spectroscopy, peripheral endothelial response by EndoPAT and endothelial-specific blood biomarkers. Twenty patients with cerebral small-vessel disease stroke (3 women, 17 men), mean age 67.1 ± 9.6, were included. The baseline mean values ± standard deviations were as follows: blood flow velocity in the middle cerebral artery, 57.4 ± 10.8 cm/s; blood oxygen saturation in the cortical microvasculature, 67.0 ± 8.2%; systolic blood pressure, 145.8 ± 19.5 mmHg; and diastolic blood pressure, 81.3 ± 9.1 mmHg. We found that tadalafil significantly increased blood oxygen saturation in the cortical microvasculature at 180 min post-administration with a mean difference of 1.57 ± 3.02%. However, we saw no significant differences in transcranial Doppler measurements over time. Tadalafil had no effects on peripheral endothelial function assessed by EndoPAT and endothelial biomarker results conflicted. Our findings suggest that tadalafil may improve vascular parameters in patients with cerebral small-vessel disease stroke, although the effect size was small. Increased oxygenation of cerebral microvasculature during tadalafil treatment indicated improved perfusion in the cerebral microvasculature, theoretically presenting an attractive new therapeutic target in cerebral small-vessel disease. Future studies of the effect of long-term tadalafil treatment on cerebrovascular reactivity and endothelial function are needed to evaluate general microvascular changes and effects in cerebral small-vessel disease and stroke.
Collapse
Affiliation(s)
- Joakim Ölmestig
- Department of Neurology, Neurovascular Research Unit, Herlev Gentofte Hospital, University of Copenhagen, Herlev 2730, Denmark
| | - Ida R Marlet
- Department of Neurology, Neurovascular Research Unit, Herlev Gentofte Hospital, University of Copenhagen, Herlev 2730, Denmark
| | - Rasmus H Hansen
- Department of Radiology, Herlev Gentofte Hospital, Herlev 2730, Denmark
| | - Shazia Rehman
- Department of Radiology, Herlev Gentofte Hospital, Herlev 2730, Denmark
| | - Rikke Steen Krawcyk
- Department of Neurology, Neurovascular Research Unit, Herlev Gentofte Hospital, University of Copenhagen, Herlev 2730, Denmark.,Department of Physiotherapy and Occupational Therapy, Herlev Gentofte Hospital, Herlev 2730, Denmark
| | - Egill Rostrup
- Center for Neuropsychiatric Schizophrenia Research, Mental Health Center Glostrup, Capital Region Psychiatry, Glostrup 2600, Denmark
| | - Kate L Lambertsen
- Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, Odense 5000, Denmark.,Department of Neurology, Odense University Hospital, Odense 5000, Denmark.,BRIDGE-Brain Research Inter-Disciplinary Guided Excellence, Department of Clinical Research, University of Southern Denmark, Odense 5000, Denmark
| | - Christina Kruuse
- Department of Neurology, Neurovascular Research Unit, Herlev Gentofte Hospital, University of Copenhagen, Herlev 2730, Denmark.,Institute for Clinical Medicine, University of Copenhagen, 2200 Copenhagen N, Denmark
| |
Collapse
|
6
|
Aragonez CG, de Beer VJ, Tharp DL, Bowles DK, Laughlin MH, Merkus D, Duncker DJ, Bender SB. Differential impact of severe familial hypercholesterolemia on regional skeletal muscle and organ blood flows during exercise: Effects of PDE5 inhibition. Microcirculation 2019; 26:e12539. [PMID: 30821858 DOI: 10.1111/micc.12539] [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: 12/14/2018] [Revised: 01/22/2019] [Accepted: 02/25/2019] [Indexed: 12/01/2022]
Abstract
OBJECTIVE Swine with familial hypercholesterolemia (FH) exhibit attenuated exercise-induced systemic vasodilation that is restored by phosphodiesterase 5 (PDE5) inhibition. Whether the impacts of FH and PDE5 inhibition to impair and restore exercise-induced vasodilation, respectively, results from tissue-specific or generalized effects remains unclear. Thus, we hypothesized that FH induces generalized impairment of skeletal muscle vasodilation that would be alleviated by PDE5 inhibition. METHODS Systemic vascular responses to exercise were assessed in chronically instrumented normal and FH swine before and after PDE5 inhibition with EMD360527. Skeletal muscle and organ blood flows and conductances were determined via the microsphere technique. RESULTS As previously reported, vs normal swine, FH swine have pronounced elevation of total cholesterol and impaired exercise-induced vasodilation that is restored by PDE5 inhibition. Blood flows to several, not all, skeletal muscle vascular beds were severely impaired by FH associated with reduced blood flow to many visceral organs. PDE5 inhibition differentially impacted skeletal muscle and organ blood flows in normal and FH swine. CONCLUSIONS These data indicate that FH induces regional, not generalized, vasomotor dysfunction and that FH and normal swine exhibit unique tissue blood flow responses to PDE5 inhibition thereby adding to accumulating evidence of vascular bed-specific dysfunction in co-morbid conditions.
Collapse
Affiliation(s)
- Christian G Aragonez
- Biomedical Sciences, University of Missouri, Columbia, Missouri.,Research Service, Harry S Truman Memorial Veterans Hospital, Columbia, Missouri
| | - Vincent J de Beer
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Cardiovascular Research School COEUR, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Darla L Tharp
- Biomedical Sciences, University of Missouri, Columbia, Missouri
| | - Douglas K Bowles
- Biomedical Sciences, University of Missouri, Columbia, Missouri.,Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri.,Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri
| | - M Harold Laughlin
- Biomedical Sciences, University of Missouri, Columbia, Missouri.,Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri.,Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri
| | - Daphne Merkus
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Cardiovascular Research School COEUR, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Dirk J Duncker
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Cardiovascular Research School COEUR, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Shawn B Bender
- Biomedical Sciences, University of Missouri, Columbia, Missouri.,Research Service, Harry S Truman Memorial Veterans Hospital, Columbia, Missouri.,Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
| |
Collapse
|
7
|
Piil P, Jørgensen TS, Egelund J, Gliemann L, Hellsten Y, Nyberg M. Effect of high-intensity exercise training on functional sympatholysis in young and older habitually active men. TRANSLATIONAL SPORTS MEDICINE 2018. [DOI: 10.1002/tsm2.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- P. Piil
- Department of Nutrition, Exercise and Sports; University of Copenhagen; Copenhagen Denmark
| | - T. S. Jørgensen
- Department of Nutrition, Exercise and Sports; University of Copenhagen; Copenhagen Denmark
- Department of Orthopedics; Herlev and Gentofte Hospital; Copenhagen Denmark
| | - J. Egelund
- Department of Nutrition, Exercise and Sports; University of Copenhagen; Copenhagen Denmark
| | - L. Gliemann
- Department of Nutrition, Exercise and Sports; University of Copenhagen; Copenhagen Denmark
| | - Y. Hellsten
- Department of Nutrition, Exercise and Sports; University of Copenhagen; Copenhagen Denmark
| | - M. Nyberg
- Department of Nutrition, Exercise and Sports; University of Copenhagen; Copenhagen Denmark
| |
Collapse
|
8
|
|
9
|
Smooth Muscle Phenotypic Diversity: Effect on Vascular Function and Drug Responses. ADVANCES IN PHARMACOLOGY 2017. [PMID: 28212802 DOI: 10.1016/bs.apha.2016.07.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
At its simplest resistance to blood flow is regulated by changes in the state of contraction of the vascular smooth muscle (VSM), a function of the competing activities of the myosin kinase and phosphatase determining the phosphorylation and activity of the myosin ATPase motor protein. In contrast, the vascular system of humans and other mammals is incredibly complex and highly regulated. Much of this complexity derives from phenotypic diversity within the smooth muscle, reflected in very differing power outputs and responses to signaling pathways that regulate vessel tone, presumably having evolved over the millennia to optimize vascular function and its control. The highly regulated nature of VSM tone, described as pharmacomechanical coupling, likely underlies the many classes of drugs in clinical use to alter vascular tone through activation or inhibition of these signaling pathways. This review will first describe the phenotypic diversity within VSM, followed by presentation of specific examples of how molecular diversity in signaling, myofilament, and calcium cycling proteins impacts arterial smooth muscle function and drug responses.
Collapse
|
10
|
Di Luigi L, Sansone M, Sansone A, Ceci R, Duranti G, Borrione P, Crescioli C, Sgrò P, Sabatini S. Phosphodiesterase Type 5 Inhibitors, Sport and Doping. Curr Sports Med Rep 2017; 16:443-447. [DOI: 10.1249/jsr.0000000000000422] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|