Expressions of PPAR γ protein during the course of pancreatic fibrosis of chronic pancreatitis in Wistar rats / 中华胰腺病杂志

ABSTRACT

ObjectiveTo observe the expressions of PPAR-γ protein during the course of pancreatic fibrosis of chronic pancreatitis (CP) in Wistar rats and its significance.Methods Bibutyltin dichloride ( DBTC,8 mg/kg body weight) in a volume of 200 ml solvent was injected into the tail vein to establish the CP rat's model.Wistar rats were randomly divided into control group and 1,3,5,7,14,42 d group according to weights.Pancreatic tissue underwent routine pathological examination,and collagen accumulation in pancreatic sections was determined by staining for Sirius Red.Pancreatic myeloperoxidase (MPO)activity was determined.Expressions of α-SMA and PPAR-γ proteins were assessed by immunohistochemical method.Results Light microscopy showed signs of acute pancreatitis with interstitial edema and infiltration of neutrophilic granulocytes 7 d after DBTC injection.Acinar cells necrosis,atrophy,lymphocytes and monocytes infiltration,fibrosis within lobule and peri-lobule as well as pancreatic duct changes were found,which was in accord with the course from AP to CP.One days after induction,the activity of MPO,expressions of α-SMA was significantly increased[ (0.78 ±0.71) vs (0.15 ±0.05)U/g,6.67 ±3.14 vs 0,P＜0.05],then it did not increase with time of induction.Seven days after induction,collagen level reached the peak [ (45.42 ±15.99)％ ],which was significantly higher than that in control group [ (10.87 ± 2.28 )％,P ＜ 0.05 ].Collagen fibers accumulated from periductal to intra-acinar and/or inter-acinar areas.In control rats,the expression of PPAR-γ protein was positive only in vessel walls,and the expression level was 0.17±0.41 and increased with time of induction,then reached the peak of 4.83 ± 2.71 at 42 d.ConclusionsDuring the course of pancreatic fibrosis in rats,the expression of PPAR-γ protein is gradually increased,and plays a limited anti-inflammation and anti-fibrosis role.