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Zhang X, Hiam D, Hong YH, Zulli A, Hayes A, Rattigan S, McConell GK. Nitric oxide is required for the insulin sensitizing effects of contraction in mouse skeletal muscle. J Physiol 2017; 595:7427-7439. [PMID: 29071734 DOI: 10.1113/jp275133] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 10/18/2017] [Indexed: 01/15/2023] Open
Abstract
KEY POINTS People with insulin resistance or type 2 diabetes can substantially increase their skeletal muscle glucose uptake during exercise and insulin sensitivity after exercise. Skeletal muscle nitric oxide (NO) is important for glucose uptake during exercise, although how prior exercise increases insulin sensitivity is unclear. In the present study, we examined whether NO is necessary for normal increases in skeletal muscle insulin sensitivity after contraction ex vivo in mouse muscle. The present study uncovers, for the first time, a novel role for NO in the insulin sensitizing effects of ex vivo contraction, which is independent of blood flow. ABSTRACT The factors regulating the increase in skeletal muscle insulin sensitivity after exercise are unclear. We examined whether nitric oxide (NO) is required for the increase in insulin sensitivity after ex vivo contractions. Isolated C57BL/6J mouse EDL muscles were contracted for 10 min or remained at rest (basal) with or without the NO synthase (NOS) inhibition (NG -monomethyl-l-arginine; l-NMMA; 100 μm). Then, 3.5 h post contraction/basal, muscles were exposed to saline or insulin (120 μU ml-1 ) with or without l-NMMA during the last 30 min. l-NMMA had no effect on basal skeletal muscle glucose uptake. The increase in muscle glucose uptake with insulin (57%) was significantly (P < 0.05) greater after prior contraction (140% increase). NOS inhibition during the contractions had no effect on this insulin-sensitizing effect of contraction, whereas NOS inhibition during insulin prevented the increase in skeletal muscle insulin sensitivity post-contraction. Soluble guanylate cyclase inhibition, protein kinase G (PKG) inhibition or cyclic nucleotide phosphodiesterase inhibition each had no effect on the insulin-sensitizing effect of prior contraction. In conclusion, NO is required for increases in insulin sensitivity several hours after contraction of mouse skeletal muscle via a cGMP/PKG independent pathway.
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Affiliation(s)
- Xinmei Zhang
- Institute of Sport, Exercise and Active Living (ISEAL), College of Sport and Exercise Science, Victoria University, Melbourne, VIC, Australia.,School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC, Australia
| | - Danielle Hiam
- Institute of Sport, Exercise and Active Living (ISEAL), College of Sport and Exercise Science, Victoria University, Melbourne, VIC, Australia
| | - Yet-Hoi Hong
- Institute of Sport, Exercise and Active Living (ISEAL), College of Sport and Exercise Science, Victoria University, Melbourne, VIC, Australia
| | - Anthony Zulli
- College of Health and Biomedicine, Victoria University, Melbourne, VIC, Australia
| | - Alan Hayes
- Institute of Sport, Exercise and Active Living (ISEAL), College of Sport and Exercise Science, Victoria University, Melbourne, VIC, Australia.,College of Health and Biomedicine, Victoria University, Melbourne, VIC, Australia
| | - Stephen Rattigan
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Glenn K McConell
- Institute of Sport, Exercise and Active Living (ISEAL), College of Sport and Exercise Science, Victoria University, Melbourne, VIC, Australia.,College of Health and Biomedicine, Victoria University, Melbourne, VIC, Australia
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Abstract
Muscle dysfunction often occurs in patients with chronic obstructive pulmonary disease (COPD) and may involve both respiratory and locomotor (peripheral) muscles. The loss of strength and/or endurance in the former can lead to ventilatory insufficiency, whereas in the latter it limits exercise capacity and activities of daily life. Muscle dysfunction is the consequence of complex interactions between local and systemic factors, frequently coexisting in COPD patients. Pulmonary hyperinflation along with the increase in work of breathing that occur in COPD appear as the main contributing factors to respiratory muscle dysfunction. By contrast, deconditioning seems to play a key role in peripheral muscle dysfunction. However, additional systemic factors, including tobacco smoking, systemic inflammation, exercise, exacerbations, nutritional and gas exchange abnormalities, anabolic insufficiency, comorbidities and drugs, can also influence the function of both respiratory and peripheral muscles, by inducing modifications in their local microenvironment. Under all these circumstances, protein metabolism imbalance, oxidative stress, inflammatory events, as well as muscle injury may occur, determining the final structure and modulating the function of different muscle groups. Respiratory muscles show signs of injury as well as an increase in several elements involved in aerobic metabolism (proportion of type I fibers, capillary density, and aerobic enzyme activity) whereas limb muscles exhibit a loss of the same elements, injury, and a reduction in fiber size. In the present review we examine the current state of the art of the pathophysiology of muscle dysfunction in COPD.
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Affiliation(s)
- Joaquim Gea
- Servei de Pneumologia, Hospital del Mar-IMIM, Universitat Pompeu Fabra, Barcelona, Spain
- CIBER de Enfermedades Respiratorias (CIBERES), ISCIII, Bunyola, Spain
| | - Alvar Agustí
- CIBER de Enfermedades Respiratorias (CIBERES), ISCIII, Bunyola, Spain
- Servei de Pneumologia, Institut del Tòrax. Hospital Clínic-IDIBAPS, Universitat de Barcelona, Barcelona, Spain; and
- Fundació Investigació Sanitària Illes Balears (FISIB), Mallorca, Spain
| | - Josep Roca
- CIBER de Enfermedades Respiratorias (CIBERES), ISCIII, Bunyola, Spain
- Servei de Pneumologia, Institut del Tòrax. Hospital Clínic-IDIBAPS, Universitat de Barcelona, Barcelona, Spain; and
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Gea J, Casadevall C, Pascual S, Orozco-Levi M, Barreiro E. Respiratory diseases and muscle dysfunction. Expert Rev Respir Med 2012; 6:75-90. [PMID: 22283581 DOI: 10.1586/ers.11.81] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Many respiratory diseases lead to impaired function of skeletal muscles, influencing quality of life and patient survival. Dysfunction of both respiratory and limb muscles in chronic obstructive pulmonary disease has been studied in depth, and seems to be caused by the complex interaction of general (inflammation, impaired gas exchange, malnutrition, comorbidity, drugs) and local factors (changes in respiratory mechanics and muscle activity, and molecular events). Some of these factors are also present in cystic fibrosis and asthma. In obstructive sleep apnea syndrome, repeated exposure to hypoxia and the absence of reparative rest are believed to be the main causes of muscle dysfunction. Deconditioning appears to be crucial for the functional impairment observed in scoliosis. Finally, cachexia seems to be the main mechanism of muscle dysfunction in advanced lung cancer. A multidimensional therapeutic approach is recommended, including pulmonary rehabilitation, an adequate level of physical activity, ventilatory support and nutritional interventions.
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Affiliation(s)
- Joaquim Gea
- Servei de Pneumologia, Hospital del Mar-IMIM, Departament de Ciències Experimentals i de la Salut (CEXS), Universitat Pompeu Fabra, CIBER de Enfermedades Respiratorias ISC III, Barcelona, Catalunya, Spain.
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Genders AJ, Bradley EA, Rattigan S, Richards SM. cGMP phosphodiesterase inhibition improves the vascular and metabolic actions of insulin in skeletal muscle. Am J Physiol Endocrinol Metab 2011; 301:E342-50. [PMID: 21653225 DOI: 10.1152/ajpendo.00691.2010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
There is considerable support for the concept that insulin-mediated increases in microvascular blood flow to muscle impact significantly on muscle glucose uptake. Since the microvascular blood flow increases with insulin have been shown to be nitric oxide-dependent inhibition of cGMP-degrading phosphodiesterases (cGMP PDEs) is predicted to enhance insulin-mediated increases in microvascular perfusion and muscle glucose uptake. Therefore, we studied the effects of the pan-cGMP PDE inhibitor zaprinast on the metabolic and vascular actions of insulin in muscle. Hyperinsulinemic euglycemic clamps (3 mU·min(-1)·kg(-1)) were performed in anesthetized rats and changes in microvascular blood flow assessed from rates of 1-methylxanthine metabolism across the muscle bed by capillary xanthine oxidase in response to insulin and zaprinast. We also characterized cGMP PDE isoform expression in muscle by real-time PCR and immunostaining of frozen muscle sections. Zaprinast enhanced insulin-mediated microvascular perfusion by 29% and muscle glucose uptake by 89%, while whole body glucose infusion rate during insulin infusion was increased by 33% at 2 h. PDE2, -9, and -10 were the major isoforms expressed at the mRNA level in muscle, while PDE1B, -9A, -10A, and -11A proteins were expressed in blood vessels. Acute administration of the cGMP PDE inhibitor zaprinast enhances muscle microvascular blood flow and glucose uptake response to insulin. The expression of a number of cGMP PDE isoforms in skeletal muscle suggests that targeting specific cGMP PDE isoforms may provide a promising avenue for development of a novel class of therapeutics for enhancing muscle insulin sensitivity.
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Affiliation(s)
- A J Genders
- Menzies Research Institute, University of Tasmania, Hobart 7001, Tasmania, Australia
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Gur S, Sikka SC, Hellstrom WJG. Novel phosphodiesterase-5 (PDE5) inhibitors in the alleviation of erectile dysfunction due to diabetes and ageing-induced oxidative stress. Expert Opin Investig Drugs 2008; 17:855-64. [PMID: 18491987 DOI: 10.1517/13543784.17.6.855] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Diabetes and ageing are associated with erectile dysfunction (ED). Under these conditions, increased oxidative stress produces superoxide ions, which in turn suppresses the nitric oxide-cyclic guanosine monophosphate pathway. The phophodiesterase-5 (PDE5) inhibitors still remain ineffective in 15 - 57% of impotent men. OBJECTIVE To identify the efficacy of conventional and novel PDE5 inhibitors on oxidative stress involved in diabetes and ageing. METHODS An electronic search of the literature was conducted to review published information relating diabetes and ageing to ED and to cover late-stage developments of novel PDE5 inhibitors. RESULTS/CONCLUSION Safe and more efficacious alternatives that can modulate PDE5 levels in ED regarding oxidative stress conditions are needed. Included in this review are updates on the new PDE5 inhibitors avanafil, udenafil, SLx-2101, and mirodenafil.
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Affiliation(s)
- Serap Gur
- Tulane University Health Sciences Center, Department of Urology, 1430 Tulane Avenue, SL-42, New Orleans, LA 70112, USA
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Ayala JE, Bracy DP, Julien BM, Rottman JN, Fueger PT, Wasserman DH. Chronic treatment with sildenafil improves energy balance and insulin action in high fat-fed conscious mice. Diabetes 2007; 56:1025-33. [PMID: 17229936 DOI: 10.2337/db06-0883] [Citation(s) in RCA: 183] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Stimulation of nitric oxide-cGMP signaling results in vascular relaxation and increased muscle glucose uptake. We show that chronically inhibiting cGMP hydrolysis with the phosphodiesterase-5 inhibitor sildenafil improves energy balance and enhances in vivo insulin action in a mouse model of diet-induced insulin resistance. High-fat-fed mice treated with sildenafil plus L-arginine or sildenafil alone for 12 weeks had reduced weight and fat mass due to increased energy expenditure. However, uncoupling protein-1 levels were not increased in sildenafil-treated mice. Chronic treatment with sildenafil plus L-arginine or sildenafil alone increased arterial cGMP levels but did not adversely affect blood pressure or cardiac morphology. Sildenafil treatment, with or without l-arginine, resulted in lower fasting insulin and glucose levels and enhanced rates of glucose infusion, disappearance, and muscle glucose uptake during a hyperinsulinemic (4 mU x kg(-1) x min(-1))-euglycemic clamp in conscious mice. These effects occurred without an increase in activation of muscle insulin signaling. An acute treatment of high fat-fed mice with sildenafil plus l-arginine did not improve insulin action. These results show that phosphodiesterase-5 is a potential target for therapies aimed at preventing diet-induced energy imbalance and insulin resistance.
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Affiliation(s)
- Julio E Ayala
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, 2200 Pierce Ave., 702 Light Hall, Nashville, TN 37232, USA.
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Hoseini S, . HE, . AM, . MA. Effects of Sildenafil a Phosphodiesterase 5 Inhibitor on Rat Liver Cell Key Enzymes of Gluconeogenesis and Glycogenolysis. INT J PHARMACOL 2006. [DOI: 10.3923/ijp.2006.280.285] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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