Effects of somatestatin analogues on pancreatic tissue TGF-β1 expression in acute pancreatitis in rats and its mechanisms

Objective To determine the effects and mechanisms of somatostatin analogues (sandostatin) on pancreatic repair and regeneration in caerulein-induced pancreatitis. Methods Acute pancreatitis was induced by intra-abdominal infusion of caerulein in rats, sandostatin was administered intra-abdominally at the time of induction of pancreatitis and 24, 48 and 72 hours after. Rats were sacrificed at 6, 24, 48, 72 and 96 hours after the operation. The mRNA expression for Transforming growth factor β1 (TGF-β1) was evaluated by reverse transcription-polymerase chain reaction, pancreatic tissue DNA synthesis was measured by 3H-thymidine method in vitro and protein content was detected by Lowry's method. Results The serum amylase level was decreased significantly in the sandostatin-treated group. Expression of TGF-β1 mRNA was undetectable in the normal pancreas and the treated group at 6 hours. TGF-β2 was observed at 24 hours after the induction of pancreatitis, reaching maximum at 72 hours. It could be detected in the sandostatin-treated group at 6 hours, reaching maximum at 24 hours, the expression of TGF-β1 was increased significantly in the sandostatin-treated group as compared with the non-treated group at 24, 48 hours. Pancreatic tissue DNA synthesis showed a significant decrease during the first 72 hours following the induction of pancreatitis and a marked increase was observed at 96 hours after treatment with sandostatin. Within 48 hours of the induction of pancreatitis, total protein content in pancreatic tissue declined, and there was a significant increase in the sandostatin-treated group at 48 hours, reaching maximum at 96 hours. Conclusions Effects of somatostatin analogues (sandostatin) on pancreatic tissue regeneration in acute pancreatitis in rats might be attributed to the enhancement of TGF-β1 gene expression which subsequently stimulates formation of extracellular matrix components, increases protein content and DNA synthesis, thus accelerates pancreatic repair and regeneration.