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.