Inhibition of prostaglandin E2-induced cyclic amp accumulation in the rat anterior pituitary by 11-deoxyprostaglandin E analogs (9-ketoprostynoic acids).

The effects of various 11-deoxyprostaglandin E analogs on the basal and prostaglandin E2 (PGE2)-induced cyclic AMP accumulation in the rat anterior pituitary were studied in vitro. 13-Hydroxy-9-oxoprost-14-ynoic acid at 5 X 10(-4)M but not 5 X 10(-5)M, decreased (45%) the induced accumulation and did not alter the basal accmulation; 15-hydroxy-9-oxoprost-13-ynoic acid at 5 X 10(-4)M caused less of a decrease (29%) in the induced and also did not alter the basal accumulation. (14Z)-13-Hydroxy-9-oxoprost-14-enoic acid at 5 X 10(-4)M did not alter the induced and caused a slight increase (5 fold) in the basal accumulation. 7-Oxa-13-prostynoic acid increased slightly the basal accumulation at 5 X 10(-5)M (2 fold) and 2.33 X 10(-4)M (6-fold) and did not antagonize the induced accumulation. Thus, the 9-ketoprostynoic acids are effective PGE2 antagonists in this system.