Protection by Hypothermia of Hypoxia-Induced Inhibition of Neurogenic Vasodilation in Porcine Cerebral Arteries

Journal of Pharmacological Sciences

Kazuhide Ayajiki¹  Hideyuki Fujioka¹  Noboru Toda¹  Toshiki Tanaka¹  Tomio Okamura¹ 

[1]Department of Pharmacology, Shiga University of Medical Science

关键词: hypoxia;    hypothermia;    nitroxidergic (nitrergic) nerve;    cerebral artery;   

DOI  :  10.1254/jphs.92.93

学科分类：药学

来源: Nihon Yakuri Gakkai Henshuubu / Japanese Pharmacological Society

【 摘 要 】

References(26)Cited-By(2)Porcine cerebral arterial strips denuded of the endothelium responded to transmural electrical stimulation (5 Hz for 40 s) with a relaxation, which was abolished by tetrodotoxin and N G-nitro-L-arginine, a NO synthase inhibitor. Lowering the temperature of the bathing media from 37°C to 33°C or 25°C potentiated the response to nerve stimulation, but did not affect relaxations induced by NO applied exogenously. Hypoxia suppressed the stimulation-induced relaxation at 37°C, but hypothermia blunted the inhibitory effect of hypoxia in a temperature-dependent manner. It is concluded that hypothermia augments vasodilatation associated with nitroxidergic (nitrergic) nerve activation possibly by increasing the production of NO from L-arginine and, in addition, prevents impairment of NO production by hypoxia. These mechanisms likely explain how hypothermia protects nerve cells against hypoxia. Inhibitions of cyclic GMP phosphodiesterase and of superoxide production by hypoxia do not seem to participate in the action of hypothermia. Mechanisms underlying its protective action remain to be ascertained.

【 授权许可】

Unknown