Effect of intraventricular administration of anti-somatostatin gamma-globulin on the lethal dose-50 of strychnine and pentobarbital in rats.

Effects of intraventricular injection of sheep anti-somatostatin gamma-globulin (anti-SSG) on strychnine-induced seizures, strychnine LD50, and pentobarbital LD50 were examined in male rats under light ether anesthesia. Ten microliters of anti-SSG given 2 h earlier significantly decreased the duration of strychnine-induced seizures as compared with that in the control rats pretreated with normal sheep gamma-globulin (NSG). This effect of anti-SSG seemed to be specific, as there was no difference in seizure duration between sheep anti-LHRH gamma-globulin (anti-LHRHG)- and NSG-pretreated rats. Survival rates in anti-SSG-pretreated rats after injection of strychnine and pentobarbital were significantly larger (P less than 0.01 and P less than 0.05, respectively) than those in the control rats receiving NSG. The administration of anti-SSG resulted in 26.7% and 22.9% increases in the LD50 of strychnine and pentobarbital, respectively. These results indicate that endogenous somatostatin in the cerebrospinal fluids and/or the periventricular tissue nodulates the response of the central nervous system to strychnine and pentobarbital in rats.