A sex-related difference in the neurobehavioral and hepatic effects following chronic endosulfan treatment in rats

The neurobehavioral and hepatic effects following chronic endosulfan administration were studied in adult male and female rats. The neurobehavioral effect was determined by testing spontaneous motor activity, motor coordination and learning and memory processes in rats of either sex, 30 days after treating the animal orally with endosulfan (3.0 and 6.0 mg/kg per day). Mortality occurring during the treatment and body weight gain at the termination of treatment were also recorded. Liver weight and liver and serum concentrations of glutamic oxaloacetic transamine, glutamic pyruvic transaminase and acetylinesterase were measured in order to determine the hepatotoxic effect of endosulfan. Body weight gain, motor coordination and acetylcholinesterase activity were unaltered in either sex. Learning and memory processes were impaired in both groups indistinguishably. Liver weight and liver and serum transaminases concentrations were increased more markedly in female than in male animals. A 30% mortality occurred in female group that received 6 mg/kg of endosulfan. Endosulfan stimulated spontaneous motor activity more markedly in male than in female animals. These findings suggest that a sex-related difference seems to occur in the stimulation of spontaneous motor activity, liver injury and mortality that result from repeated exposure to sublethal doses of endosulfan in rats.