Prostanoid generation in early stages of acute pancreatitis: a role for nitric oxide

The role of nitric oxide in eicosanoid and oxygen-free radical production in the early stages of sodium taurocholate-induced acute necrotizing pancreatitis has been studied. Male Wistar rats were divided into three groups: group I: control group, a volume of 0.1 ml/100 g body wt saline solution was injected at low pressure in the pancreatic duct; group II: acute pancreatitis was induced by administration of 3.5% sodium taurocholate; and group III: intravenous administration of NG-nitro-L-arginine methyl esther (a nitric oxide synthase inhibitor) 5 min before induction of acute pancreatitis as stated for group II. At 5 and 60 min after induction of pancreatitis, blood and pancreas tissue samples were taken for assays. Increases in 6-keto PGF1 alpha, TXB2, PGE2, PGF2 alpha, and 12-HETE were observed in the pancreatic tissue. Lipoperoxidation was also enhanced and remained unaltered after nitric oxide inhibition. The fact that nitric oxide synthase inhibition could only reverse the increases in 6-keto PGF1 alpha and TXB2 levels indicates that in acute pancreatitis endothelial and platelet eicosanoid generation is mediated through an nitric oxide-dependent mechanism. In contrast, nitric oxide appears to be not related with oxygen free radical damage associated with acute pancreatitis.