Objective To investigate the relationship between sonic hedgehog(SHH)signaling pathway and chronic pancreatitis.Methods Thirty Wistar rats were randomly divided into the model group,experimental control group and blank control group,and there were 10 rats in each group.Trinitrobenzene sulfonic acid was infused into the pancreatic duct of the rats to induce pancreatitis in the model group.The pancreatic duct of the rats in the experimental control group were infused with 0.9％ sodium chloride solution.No treatment was performed on rats in the blank control group.The serum levels of bilirubin and amylase of the 3 groups were determined,and the histopathological alterations were studied.Expressions of patched-1(PTCH-1),smoothened (SMO)and SHH were detected by immunohistochemistry.All data were analyzed using the analysis of variance or Student's t test.Results The levels of total bilirubin(TBil)in the model group,experimental control group and blank control group from day 1 to day 35 were(3.17 ±0.21)μmol/L-(9.28 ±2.15)μmol/L,(3.44 ±0.54)μmol/L-(3.76 ± 0.15)μmol/L,(2.45 ± 0.32)μmol/L-(3.27 ± 1.43)μmol/L,respectively.The levels of amylase in the model group,experimental control group and blank control group were(1124 ± 143)U/L-(1522 ± 169)U/L,(1123 ± 104)U/L-(1007 ± 141)U/L,(1014 ± 115)U/L-(1013 ± 142)U/L,respectively.Compared with the experimental group and the blank control group,the serum levels of TBil and amylase in the model group were increased significantly from day 7 to day 35(F =14.81,16.27,18.13,11.49,17.91;11.54,10.24,12.64,21.11,15.38,P ＜ 0.05),and fibrotic proliferation of pancreatic tissues were found at day 35;the expressions of PTCH-1,SMO and SHH in the pancreatic tissue was increased significantly in the model group.Conclusion SHH signaling pathway is activated in the tissue of pancreatitis in rats,it might play an important role in the genesis of pancreatitis.