Adenyl cyclase and cyclic AMP (cAMP) in acute experimental pancreatitis.

The level of adenosine 3':5'-cyclic monophosphate (cAMP) and the activity of adenyl cyclase were studied in the pancreas under normal conditions and during acute hemorrhagic pancreatitis induced by intraductal injection of fresh trypsin-bile-blood mixture. In addition, the adenyl cyclase was localized histochemically in the pancreas. Basal cAMP concentration and adenyl cyclase activity were 0.88 +/- 0.11 pmoles/mg wet tissue and 3.39 +/- 0.21 pmoles/mg protein/min, respectively. The acute pancreatitis drastically reduced the adenyl cyclase activity at 15 minutes to 1.66 +/- 0.54 pmoles/mg protein/min, and totally suppressed adenyl cyclase activity at 30 minutes after the onset of pancreatitis without affecting cAMP levels. The presence of sodium fluoride in the incubation medium prolonged the enzyme activity up to 45 minutes. The progressive disappearance of adenyl cyclase activity presumably resulted from the destruction of cellular integrity caused by autodigestion by the active proteolytic enzymes released during pancreatitis.

Cyclic Amp and the release of antral gastrin.

The isolated, vagally innervated antral pouches in anesthetized dogs were irrigated with 095% acetylcholine chloride (Ach) or a 0.4 M mixture of non-essential amino acids (AA), or distended at 30 cm H2O pressure. In addition,2-deoxy-D-glucose (2-DG) was administered intravenously. Significant increases in antral venous gastrin, caused by gastrin releasers, were associated with a significant rise in cAMP content in the antral mucosa. Acidification of the antrum with simultaneous administration of 2-DG, and acidified AA abolished gastrin release, and significantly reduced mucosal cAMP. Acidified Ach and distension of the antrum with 0.1 N HC1 supressed gastrin levels without significantly changing the mucosal cAMP content. Since the augmented gastrin release was accompanied by an increased mucosal cAMP, the results suggest that cAMP participates in the action of gastrin secretagogues.