Abstract
SUMMARY: Ovulation was induced in immature mice by pregnant mare serum gonadotrophin. Reserpine in doses of 6–9 μg. prevented ovulation in these animals. Methoserpidine (up to 333 μg.) did not reduce the incidence of ovulation. A single dose of 2 mg. α-methyldopa was without effect but several doses at intervals inhibited ovulation. Groups of mice treated with gonadotrophin and reserpine were pretreated with other drugs. α-Methyldopa decreased the sedative effect of reserpine but not its inhibitory effect on ovulation. Dopa antagonized both effects of reserpine. 5-Hydroxytryptamine creatinine sulphate in doses of 100 or 200 μg. injected s.c. 16 or 17 hr. before the mice were killed consistently increased the percentage ovulating in response to gonadotrophin. A significant increase was also obtained when 5-hydroxytryptophan was injected into mice pretreated with iproniazid.