Experimental Study On The Influence Of The Apoptosis-associated Gene Expression Of Octreotide In Hepatocytes Apoptosis Induced By PAAF In Rats

Objective To investigate the mechanism of liver injury induced by PAAF and the influence of Octreotide on the apoptosis-associated gene expression and its probable mechanism to protect hepatocytes in rats. Methods 48 Sprague-Dawley(SD) rats, male or female, were randomly divided into three groups: group A served as the control group and 8ml normal saline(NS) was injected into the peritoneal cavity; group B as the model group, 8ml PAAF was injected; group C as the treatment group ,lh before and 2h, 5h after 8ml PAAF was injected Octreotide was administrated subcutaneous, with the dose of 4μg/Kg and 20μg/Kg; respectively NS replaced Octreotide in group A and B with the same volume. After peritoneal cavity injection the rats were put to death in two batches at 4h and 7h, eight rats per batches. Liver and pancreas samples were analyzed for histopathology with fluorescence microscope (FM) and transmission electron microscope (TEM). The apoptosis ratio of hepatocytes and its cell cycle distribution were detected using flow cytometry (FCM) with terminal deoxynucleotidyl transferase biotin-dUTP nick end labelling (TUNEL) method.and the protein expression of apoptosis-regulated gene p53, Bcl-2 was detected by immunohistochemical technique. Results Pathological results showed that there were apoptotic hepatocytes with typical morphological change in the group B and in the group C. (Apoptotic bodies flashing powerful yellow-green fluorescence were discovered by fluorescence microscope and typical apoptotic hepatocytes were detected by electron microscope,There were specific nuclear fragments in cellular plasm.).Hepatocytes were severely injured in the group B and slightly in the group C.Most pancreatic acinic cells necrosed and collapsed in group ANP,Its cell structure vanished.Compared with the group ANP, the pancreatic acinic cells in group B did not necrose notably.Comparing the group B with the group C, the pathology showed noremarkable dissimilarity. About 20.13+3.84% hepatocytes were detected apoptosis at 7h in the group B and about 49.04+1.44% hepatocytes growth ceased in the G2/M stage . P53 and Bcl-2 protein could not be detected in the group A;Compared with the group A ,the expression of p53 and bcl-2 strengthened significantly in the group B,and weakened significantly in the group C compared with B(P<0.01) Conclusion 1. The pathological changes of pancreas acinic cell were obviously different between the injured model group induced by PAAF and the ANP model. The ideal animal model for studying the protective mechanism of Octreotide on liver injury induced by PAAF was provided without the influences of the pancreatic pathology improvement. Furthermore ,PAAF can also be used for model establishment of other vital organ injury and for the study of Octreotide protective mechanism 2. By inducing hepatocytes apoptosis in nomal rats,PAAF results in liver injury . Apoptosis-associated gene P53 and Bcl-2 took part in the regulation of hepatocyte apoptosis induced by PAAF in rats. 3.Not mainly by inducing the anti-apoptosis gene expression or inhibiting the pro-apoptosis gene expression but mostly by restraining the cytokines cascade-like reaction of the Kuppfer systerm in the upper stream of apoptosis-regulated gene in liver ,Octreotide implement function of preventing hepatocyte apoptosis.