ABSTRACT
1. Calcium channel blockers (CCBs) are reported to affect extrapyramidal motor behavior in mammals. Since sex related differences are a common feature in the pharmacological properties of several centrally active drugs, the authors decided to investigate the effects of verapamil (VER), flunarizine (FLU) and nimodipine (NIM), three pharmacologically different CCBs, on neuroleptic-induced catalepsy in male and female albino mice. 2. Catalepsy was induced with haloperidol (0.75 mg/kg, i.p.) and measured at 30-min intervals by means of a bar test. Drugs (or appropriate vehicle, for the controls) were injected i.p. 20 min before haloperidol, with each animal being used only once. 3. VER (1, 5 and 10 mg/kg) did not significantly affect catalepsy in male mice. In females, however, a significant attenuation of catalepsy was found at the two higher doses. 4. FLU (1, 5 and 10 mg/kg) did not significantly affect catalepsy in male mice, whilst a significant attenuation was observed in females with the doses of 1 and 5 mg/kg (but not with the dose of 10 mg/kg). 5. NIM (3, 10 and 30 mg/kg) potentiated neuroleptic-catalepsy in males at the doses of 10 and 30 mg/kg. In females, however, only the higher dose of NIM caused a potentiation of catalepsy. 6. These results demonstrate the existence of sex related differences in the extrapyramidal effects of CCBs in mice. Further, this sex related effect might depend, among other factors, on the particular channel involved.
