Biological activity of metabolites of PGD2 on canine proximal colon

The responses of the canine colonic epithelium to the metabolites of prostaglandin D2 (PGD2) were compared with those elicited by the parent prostanoid. Dose-response relations to PGD2 showed three distinct patterns: 1) a dose-dependent decrease in short-circuit current (Isc) at lower concentrations followed by a dose-dependent increase at higher concentrations; 2) dose-dependent decreases, with no increase even at the highest concentrations …