Effect of endosulfan pretreatment on organ weights and on pentobarbital hypnosis in rats.

The effects of endosulfan on the weights of the liver, adrenal and ovary, on pentobarbital blood and brain levels and on sleeping time (ST) have been investigated in female rats after daily oral doses of 0, 1.0, 2.5 and 5.0 mg/kg for a period of 7 or 15 days. No significant change in body weight was observed. With higher doses (2.5--5.0 mg/kg) the liver weight was significantly increased, but ovary and adrenal weights did not increase. Endosulfan treatment shortened sleeping time, while induction time was significantly increased. The concentration of pentobarbital in the blood and brain of rats after 30 min and upon awakening indicated that there was a significant decrease at 30 min. No change at awakening was observed in endosulfan-treated rats as compared to controls. It is suggested tha endosulfan may shorten the duration of pentobarbital-induced sleep, perhaps by induction of hepatic microsomal enzyme activity.