Skeletal muscle contractions stimulate cGMP formation and attenuate vascular smooth muscle myosin phosphorylation via nitric oxide.
Nitric oxide generated by neuronal nitric oxide synthase in contracting skeletal muscle fibers may regulate vascular relaxation via a cGMP-mediated pathway. Neuronal nitric oxide synthase content is greatly reduced in skeletal muscles from mdx mice. cGMP formation increased in contracting extensor digitorum longus muscles in vitro from C57 control, but not mdx mice. The increase in cGMP content was abolished with NG-nitro-L-arginine. Sodium nitroprusside treatment increased cGMP levels in muscles from both C57 and mdx mice. Skeletal muscle contractions also inhibited phenylephrine-induced phosphorylation of smooth muscle myosin regulatory light chain. Arteriolar dilation was attenuated in contracting muscles from mdx but not C57 mice. NO generated in contracting skeletal muscle may contribute to vasodilation in response to exercise.
Department of Physiology, University of Texas Southwestern Medical Center at Dallas, 75235-9040, USA. Lau01@utsw.swmed.edu
K S
KS
Lau
R W
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Grange
W J
WJ
Chang
K E
KE
Kamm
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Sarelius
J T
JT
Stull
D000818:Animals; D006152:Cyclic GMP / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000098:blood supply / Q000378:metabolism / Q000502:physiology*; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D009136:Muscular Dystrophies / Q000378:metabolism; D018994:Myosin Light Chains / Q000378:metabolism; D009218:Myosins / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D010766:Phosphorylation; D005082:Physical Exertion; D014664:Vasodilation
D018994:Myosin Light Chains; D009569:Nitric Oxide; D009218:Myosins; D006152:Cyclic GMP