Pituitary Adenylate Cyclase Activating Peptide In The Pathogenesis Of Acute Pancreatitis

Pituitary Adenylate Cyclase Activating Polypeptide Aggravated Experimental Acute PancreatitisPACAP(pituitary adenylate cyclase activating polypeptide) is one kind of peptidergic transmitter, its role in the pathogenesis of acute pancreatitis remains to be elucidated. This experiment was conducted to examine the action of exogenous PACAP on rat pancreas and on the course of experimental acute pancreatitis. 5 ~ 30μg/kg of PACAP slightly increased serum amylase, induced pancreatic edema(pancreatic wet/dry weight ratio: 23.88±2.532% ~ 25.86±1.974% vs 29.21±5.657%), inflammatory cell infiltration, vacuolization of acinar cells, occasionally fatty and parenchymal necroses. 15~30μg/kg of PACAP aggravated cerulein-induced acute pancreatitis: pancreatic edema became more marked(pancreatic wet/dry weight ratio: 13.45±2. 045%~17.66±4. 652% vs 21.83 ±3. 013%, P<0.05), serum amylase higher, and ascites, pancreatic bleeding, fatty and parenchymal necroses and extensive vacuolization of acinar cells occurred. For sodium taurocholate-induced pancreatitis, 5~ 10μg/kg of PACAP mildly attenuated pancreatic edema, reduced serum amylase(1986. 91 + 710. 97~ 2944.33 + 1182.47 IU/L vs 3690. 87+2277. 99IU/L, P<0.05), while caused multifocal hemorrhage and prominent necrosis in pancreas. Except cerulein-induced pancreatitis, other groups were found to have reduced pancreatic functional capillary density(FCD). In conclusion, PACAP is proinflammatory in the pathogenesis of acute pancreatitis, PACAP plus cerulein can induce acutehemorrhagic/necrotizing pancreatitis, and the action of PACAP on cerulein-induced panceatitis possibly varied from that on sodium taurocholate-induced one.