EFFECTS OF DIPHENOXYLATE HYDROCHLORIDE AND dl-15 METHYL PROSTAGLANDIN F_2a METHYL ESTER ON RAT LUTEAL CELLS

Diphenoxylate hydrochloride (R1132) at concentrations of 10 and 20μg/ml or dl-15 methyl-PGF_2α methyl ester (PG05)at levels of 5 and 10μg/ml was shown to have no effect on progesterone secretion by luteal cells in vitro in the absence of hCG. A marked increase in progesterone level was elicited by hCG as high as 3～8 fold the original value. The steroidogenic response of luteal cells to hCG was inhibited by R1132 and PG05. R1132 at a daily dose of 10 mg/kg or PG05 at a daily dose of 0.1 mg/kg for 5 days showed no obvious effect on ovary progesterone secretion in pseudopregnant rat. However, treatment with R1132 10 mg/kg plus PG05 0.1 mg/kg resulted in a decrease in the progesterone production of ovary in vitro. R1132 and PG05 at doses of 50 mg/kg and 0.5 mg/kg, respectively, exhibited an inhibitory effect on the adenylate cyclase activity.