RESUMEN
Motor, sensory and thermoregulatoty function were examined in aging rats (12 months) following two schedules of repated po adminstration of the carbamate insecticide carbaryl and these effects were assessed in terms of blood cholinesterase activity. Administration of carbaryl (50 mg/Kg) by gavage daily for 30 days resulted in a resultad in a reduction of locomotor activity in thre open-field and an inhibition of cholinesterase activity within 30 min after the last treatment. Twenty-for h later, only the locomotor effect was evident. After 90 days of exposure to carbaryl in drinking water, no significant effects were observed. These findings suggest that repeated administration of carbaril to aging rats can induce an impairment of motor function and a reduction of cholinesterase activity, while tolerance develops in some other parameters