Regional distribution of prostaglandin-metabolizing enzymes in the mucosa of the human upper gastrointestinal tract.

The occurrence of three enzymes of prostaglandin metabolism, 15-hydroxy-prostaglandin-dehydrogenase, delta13 -reductase and prostaglandin E-9-keto-reductase was investigated in gastroscopically obtained biopsy specimens of human upper gastrointestinal mucosa. All three enzymes could be found in the mucosa of oesophagus, gastric fundus, corpus and antrum and duodenum. While the specific activity of 15-hydroxy-prostaglandin-dehydrogenase was highest and the specific activity of prostaglandin E-9-keto-reductase was lowest in all regions studied, differences of the specific activities of the enzymes between the regions are remarkably small. These results are discussed with respect to possible functions of endogenous prostaglandins in human gastrointestinal mucosa.