Effect of graded doses of PGE2 on pancreatic exocrine secretion of bicarbonate, chymotrypsin and cyclic nucleotides during i.v. infusion of secretin in man

We have previously reported that PGE2 inhibits pancreatic enzyme secretion during Secretin-Caerulein infusion, but differing results have also been reported. In this study 10 tests were performed in 5 healthy volunteers as follows: each subject received secretin (GIH) 2 CU/Kg-h by continuous infusion for 2 hours and, several days later, Secretin at the same dose plus PGE2 (Upjohn) in step-wise doses (0.04-0.08-0.12 gamma/Kg min) increasing every thirty min form 30' to 120' min. Duodenal juice was collected in 10 min samples. The volume of each sample was recorded and bicarbonate, chymotrypsin, cAMP and cGMP contents were determined. Statistical evaluation was performed by Student's "t" test for paired data and the regression test. PGE2 significantly decreased chymotrypsin concentration under Secretin. Both cyclic AMP and GMP Secretin-induced secretions were significantly increased by the highest dose of PGE2. No correlation was found in the behaviour of bicarbonate, chymotrypsin and cyclic nucleotides, but it must be noted that our data concern duodenal contents and not pure pancreatic secretion.