Cyclodiene insecticides-induced changes in the central depressive effect of chlorpromazine in rats.

Spontaneous motor activity (SMA), conditioned avoidance response (CAR), muscle coordination (MC) and pentobarbital sleep were tested in rats treated orally for 90 days with tolerated doses of the cyclodiene insecticides, aldrin (1 mg/kg) and endosulfan (2 mg/kg). The same tests were repeated in similarly treated animals after injecting chlorpromazine (4 mg/kg, i.p.). Both the insecticides shortened pentobarbital sleeping time indicating their microsomal enzyme inducing property. Aldrin suppressed SMA, CAR and MC, whereas endosulfan stimulated SMA, inhibited CAR and unaltered MC. However, their concurrent action with CPZ did not result in change in the central depressive effects of the latter, but its potency during the course of its action was altered. Its potency 15 min after injection was greater and 60-180 min later was lesser in these animals than that observed in control animals. This finding was interpreted to suggest that aldrin and endosulfan has quickened the biotransformation of CPZ and thereby shortened its duration of action. A temporary promotion of its potency was accounted to its active metabolites, since prior to inactivation, CPZ is known to be metabolized by the microsomal enzymes to active compounds.

Behavioural and biochemical changes produced by repeated oral administration of the insecticide endosulfan in immature rats.

In order to study the response of rats to repeated administration of the insecticide, endosulfan during the period of growth to maturity, food intake, body weight gain, Spontaneous Motor Activity (SMA) and Muscle Coordination (MC) were determined at regular intervals in male immature Wistar rats treated with a tolerated dose of (2 mg/kg/day) orally for 90 days. Twenty-four h after the termination of the treatment, organ weight and protein concentrations were determined. The convulsive action of picrotoxin (4 mg/kg, ip) was tested in another endosulfan-treated group. Food consumption and body weight gain decreased parallely. No changes occurred in the body tissues but for liver which was enlarged and its protein, glutamic oxaloacetic transminase and glutamic pyruvic transaminase concentrations increased. The MC was unaffected. A stimulation of SMA occurred several days (75-90) after commencing treatment and these animals responded greatly than control animals to the convulsive action of picrotoxin. These findings indicated that although endosulfan produced anorexia, there were no signs of undernourishment and motor impairment in these animals. Its toxic action were confined chiefly to the liver and central nervous system.