scholarly journals Exercise Training Modulates the Nitric Oxide Synthase Profile in Skeletal Muscle From Old Rats

2009 ◽  
Vol 64A (5) ◽  
pp. 540-549 ◽  
Author(s):  
W. Song ◽  
H.-B. Kwak ◽  
J.-H. Kim ◽  
J. M. Lawler
Author(s):  
Anatolii V. Kotsuruba ◽  
Yulia P. Korkach ◽  
Sergey O. Talanov ◽  
Olga V. Bazilyuk ◽  
Lyubov G. Stepanenko ◽  
...  

Diabetes ◽  
1997 ◽  
Vol 46 (11) ◽  
pp. 1691-1700 ◽  
Author(s):  
S. Kapur ◽  
S. Bedard ◽  
B. Marcotte ◽  
C. H. Cote ◽  
A. Marette

2015 ◽  
Vol 118 (9) ◽  
pp. 1113-1121 ◽  
Author(s):  
Yet Hoi Hong ◽  
Tony Frugier ◽  
Xinmei Zhang ◽  
Robyn M. Murphy ◽  
Gordon S. Lynch ◽  
...  

Inhibition of nitric oxide synthase (NOS) significantly attenuates the increase in skeletal muscle glucose uptake during contraction/exercise, and a greater attenuation is observed in individuals with Type 2 diabetes compared with healthy individuals. Therefore, NO appears to play an important role in mediating muscle glucose uptake during contraction. In this study, we investigated the involvement of neuronal NOSμ (nNOSμ), the main NOS isoform activated during contraction, on skeletal muscle glucose uptake during ex vivo contraction. Extensor digitorum longus muscles were isolated from nNOSμ−/−and nNOSμ+/+mice. Muscles were contracted ex vivo in a temperature-controlled (30°C) organ bath with or without the presence of the NOS inhibitor NG-monomethyl-l-arginine (L-NMMA) and the NOS substrate L-arginine. Glucose uptake was determined by radioactive tracers. Skeletal muscle glucose uptake increased approximately fourfold during contraction in muscles from both nNOSμ−/−and nNOSμ+/+mice. L-NMMA significantly attenuated the increase in muscle glucose uptake during contraction in both genotypes. This attenuation was reversed by L-arginine, suggesting that L-NMMA attenuated the increase in muscle glucose uptake during contraction by inhibiting NOS and not via a nonspecific effect of the inhibitor. Low levels of NOS activity (∼4%) were detected in muscles from nNOSμ−/−mice, and there was no evidence of compensation from other NOS isoform or AMP-activated protein kinase which is also involved in mediating muscle glucose uptake during contraction. These results indicate that NO regulates skeletal muscle glucose uptake during ex vivo contraction independently of nNOSμ.


1997 ◽  
Vol 83 (2) ◽  
pp. 434-443 ◽  
Author(s):  
Janet L. Parker ◽  
Mildred L. Mattox ◽  
M. Harold Laughlin

Parker, Janet L., Mildred L. Mattox, and M. Harold Laughlin.Contractile responsiveness of coronary arteries from exercise trained rats. J. Appl. Physiol. 83(2): 434–443, 1997.—The purpose of this study was to determine whether exercise training alters vasomotor reactivity of rat coronary arteries. In vitro isometric microvessel techniques were used to evaluate vasomotor properties of proximal left anterior artery rings (1 ring per animal) from exercise-trained rats (ET; n = 10) subjected to a 12-wk treadmill training protocol (32 m/min, 15% incline, 1 h/day, 5 days/wk) and control rats (C; n = 6) restricted to cage activity. No differences in passive length-tension characteristics or internal diameter (158 ± 9 and 166 ± 9 μm) were observed between vessesls of C and ET rats. Concentration-response curves to K+ (5–100 mM), prostaglandin F2α(10−8–10−4M), and norepinephrine (10−8–10−4) were unaltered ( P > 0.05) in coronary rings from ET rats compared with C rats; however, lower values of the concentration producing 50% of the maximal contractile response in rings from ET rats ( P = 0.05) suggest that contractile sensitivity to norepinephrine was enhanced. Vasorelaxation responses to sodium nitroprusside (10−9-10−4M) and adenosine (10−9-10−4M) were not different ( P > 0.05) between vessels of C and ET rats. However, relaxation responses to the endothelium-dependent vasodilator acetylcholine (ACh; 10−10-10−4M) were significantly blunted ( P < 0.001) in coronary rings from ET animals; maximal ACh relaxation averaged 90 ± 5 and 46 ± 12%, respectively, in vessels of C and ET groups. In additional experiments, two coronary rings (proximal and distal) were isolated from each C ( n = 7) and ET ( n = 7) animal. Proximal coronary artery rings from ET animals demonstrated decreased relaxation responses to ACh; however, ACh-mediated relaxation of distal coronary rings was not different between C and ET groups. N G-monomethyl-l-arginine (inhibitor of nitric oxide synthase) blocked ACh relaxation of all rings. l-Arginine (substrate for nitric oxide synthase) did not improve the blunted ACh relaxation in proximal coronary artery rings from ET rats. These studies suggest that exercise-training selectively decreases endothelium-dependent (ACh) but not endothelium-independent (sodium nitroprusside) relaxation responses of rat proximal coronary arteries; endothelium-dependent relaxation of distal coronary arteries is unaltered by training.


2020 ◽  
Vol 98 (5) ◽  
pp. 275-281 ◽  
Author(s):  
L.A. Mys ◽  
N.A. Strutynska ◽  
Y.V. Goshovska ◽  
V.F. Sagach

Hydrogen sulfide (H2S) is an endogenous gas transmitter with profound effects on the cardiovascular system. We hypothesized that stimulation of H2S synthesis might alleviate age-associated changes in vascular reactivity. Pyridoxal-5-phosphate (PLP), the coenzyme of H2S-synthesizing enzymes, was administrated to old male Wistar rats per os at a dose of 0.7 mg/kg body mass once a day for 2 weeks. H2S content in the aortic tissue, markers of oxidative stress, inducible nitric oxide synthase (iNOS) and constitutive nitric oxide synthase (cNOS), arginase activities, and endothelium-dependent vasorelaxation of the aortic rings were studied. Our results showed that PLP restored endogenous H2S and low molecular weight S-nitrosothiol levels in old rat aorta to the levels detected in adults. PLP significantly reduced diene conjugate content, hydrogen peroxide and peroxynitrite generation rates, and iNOS and arginase activity in the aortic tissue of old rats. PLP also greatly improved acetylcholine-induced relaxation of old rat aorta (47.7% ± 4.8% versus 18.4% ± 4.1% in old rats, P < 0.05) that was abolished by NO inhibition with N-nitro-l-arginine methyl ester hydrochloride (L-NAME) or H2S inhibition with O-carboxymethylhydroxylamine (O-CMH). Thus, PLP might be used for stimulation of endogenous H2S synthesis and correction of oxidative and nitrosative stress and vessel tone dysfunction in aging and age-associated diseases.


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