[The effect of hypothermia on the vasoconstriction and vasodilatation and concerned with vasoactive drugs].

ABSTRACT

OBJECTIVE: To investigate the changes of vasoconstriction and vasodilatation under different temperature conditions and the protective effects of Vitamin E (Vit E) against endothelial injury induced by hypothermia. METHODS: The tail arterial rings were prepared for isometric tension recording using multi wire myograph system. The effect of temperature on relaxation and construction was evaluated. Incubate the arterial rings with different concentration of Vit E when they were exposed to hypothermia, then acetylcholine (ACh)-induced endothelium-dependent relaxation was investigated to evaluate the activity of endothelial. RESULTS: (1) The hypothermia could enhanced the dose-dependent construction induced by PE in mice tail artery. (2) Exposure to hypothermia also resulted in increase of sodium nitroprusside (SNP)-induced re-After incubation with Vit E, the vascular relaxation responses to ACh increased in an endothelium-dependent manner, when compared with the hypothermia-treated group. CONCLUSION: The vascular function of constriction was attenuated by hypothermia, while the relaxation was increased. Vit E could prevent the hypothermia-induced decrease in vascular endothelial cells.