Title: OCCURRENCE OF PROSTAGLANDIN E<sub>2</sub> IN THE HUMAN STOMACH, AND A STUDY OF ITS EFFECTS ON HUMAN ISOLATED GASTRIC MUSCLE
Abstract: Human stomach mucosa contains a pharmacologically active acidic lipid which is indistinguishable from (PGE2) prostaglandin E2 by chromatography in 2 different systems, and by other tests. The concentrations present in mucosa are of the order of 1 mcg/g of wet tissue. Concentrations are similar in mucosa of the body and the pyloric part of the stomach; much smaller amounts are present in submucosa and muscle. PGE2 acts directly on both the longitudinal and the circular muscle layers of the human isolated stomach. The longitudinal muscle of the body of the stomach is contracted by doses of PGE2 which may be as low as 2x10 -9 g/ml. In contrast, PGE2 inhibits the contractions of circular muscle caused by acetylcholine or potassium.