Vasodilation of intramuscular arterioles under shear stress in dystrophin-deficient skeletal muscle is impaired through decreased nNOS expression

摘要: Duchenne muscular dystrophy (DMD) is a lethal X-linked disorder of striated muscle caused by the absence dystrophin. Recently, impairment vascular dilation under shear stress has been found in DMD, but underlying molecular mechanism not fully understood. Moreover, intramuscular arterioles, which may be key to pathogenesis, addressed yet. We examined arterioles mouse cremaster due ligation. The vasodilation was significantly impaired dystrophin-deficient mdx mice as well neuronal nitric oxide synthase (nNOS)-deficient mice; however, neither endothelial NOS-deficient nor α1-syntrophin-deficient showed any difference from control mice. These results indicate that nNOS main supplier stress-induced skeletal muscle, sarcolemmal localization indispensable for function. In contrast, response acetylcholine or sodium nitroprusside nNOS-deficient mice, suggesting pharmacological treatment using vasoactive agent ameliorate and cardiac symptoms DMD.