Endogenous prostaglandins and stimulated gastric secretion in the cat: the effect of various secretory inhibitors.

1. The effects of cimetidine, somatostatin and atropine upon the outputs of acid, pepsin, prostaglandins (PG) E and F in gastric juice secreted in response to i.v. infusions of pentagastrin and histamine (H) have been studied in the conscious gastric fistula cat. 2. At constant rate infusions secretion of PGE occurs and follows a similar pattern to that of gastric acid. However the ratio of H:PGE varies considerably and to an extent inexplicable in terms of assay variation. 3. Inhibition of acid output is matched by inhibition of the output of PGE, but changes in concentration of PGE suggest this is a volume related phenomenon. 4. It is concluded that gastric juice PGE is most unlikely to have a regulatory effect upon acid secretion.