Relative activity of prostaglandins E1, A1, E2 and A2 on lipolysis, platelet aggregation, smooth muscle and the cardiovascular system

Abstract

The relative activities of four prostaglandins (PGE1, PGA1, PGE2 and PGA2) were determined in several biological tests. They were compared as intestinal muscle stimulants on rabbit duodenum and guinea-pig ileum, as inhibitors of adrenaline-induced lipolysis in rat isolated epididymal fat, inhibitors of platelet aggregation in rabbit plasma, as vasodepressor agents in anaesthetized rats and dogs, and on both blood pressure and cardiac output in unanaesthetized dogs. Formation of PGAs by dehydration and introduction of one additional double bond virtually abolished activity in all of these systems except the cardiovascular system. PGE2 was more active than PGE1 on isolated rabbit duodenum and as an antilipolytic agent, but less active in the other systems. Only PGE1 had high potency as an inhibitor of platelet aggregation.