Acute and chronic effects of estrogen treatment on pimozide-induced catalepsy in the rat.
The effects of acute (3 days) and chronic (3 weeks) estrogen treatment on pimozide-induced catalepsy in ovariectomized female rats is described. Bar and grid tests were used to evaluate the cataleptic response to a 4 mg/kg dose of pimozide. Bar data showed that acute estrogen treatment (10 microgram/kg/day) significantly potentiated catalepsy when rats were tested 24 hours after the hormone but not if a dose-test interval of 48 hours was used. In the chronic phase catalepsy was significantly increased in both hormone treated groups (24 and 48 hours after estrogen). The grid data showed a qualitatively similar trend but did not reach significance in either the acute or chronic test phase. The difference between the two test phases may arise from the operation of independent factors in each case: the acute phase effect resulting from a central action of estrogen while the chronic data might be more typical of a metabolic effect. These, and other, possibilities are discussed.
D000818:Animals; D002369:Castration; D002375:Catalepsy / Q000139:chemically induced / Q000503:physiopathology*; D004334:Drug Administration Schedule; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D006801:Humans; D010868:Pimozide; D051381:Rats; D011919:Rats, Inbred Strains
D010868:Pimozide; D004958:Estradiol