[The protective effect of a NO-synthase inhibitor in heat shock].

Acute hypotension related to the excessive production of a potent endogenous vasodilator nitric oxide (NO) is a most important link of heat shock pathogenesis. It was shown that inhibition of inducible NO-synthase by N(W)-nitro-L-arginine (L-NNA) at 10 mg/kg reduces the mortality of animals due to heat shock, prevents the fall of arterial blood pressure and abnormal inhibition of constriction and stimulation of dilation reactions related to NO hyperproduction. A total blockade of NO synthesis by L-NNA at 300 mg/kg did not exert a protective effect from heat shock. The data obtained suggest the importance of inducible NO-synthase in heat shock pathogenesis and show promise for the application of selective inhibition of inducible NO-synthase at pathological states related to NO hyperproduction.