The effect of caerulein-induced acute pancreatitis on the levels of serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) in various rat tissues.

The effects of caerulein-induced acute pancreatitis (AP) on the levels of 5-HT and 5-HIAA in pancreas, liver, brain, kidney and different parts of the digestive tract in rats have been studied. The acute pancreatitis was induced by the continuous intravenous infusion of caerulein in the doses of 5 x 10(-6) g/kg/h and 7.5 x 10(-6) g/kg/h for 12 hours, and the 5-HT and 5-HIAA concentrations were determined by the method of Curzon and Green. The changes evoked by caerulein varied qualitatively and quantitatively between organs. The significant decrease of both 5-HT and 5-HIAA was observed in pancreas, liver, brain and kidney while in the stomach there was a significant fall of 5-HT level accompanied by the relevant increase of 5-HIAA level. In the duodenum, an opposite effect was noticed, the level of 5-HT was higher than normal whereas the 5-HIAA level was reduced. The significant decrease of the 5-HT and 5-HIAA levels in pancreas observed in the present study suggests the importance of 5-HT in the development of acute pancreatitis.