Effect Of RhKD/APP On Experimental Acute Necrosis Pancreatitis In Rats

The pathophysiology of acute pancreatitis (AP) is dangerous and has a highmortality. The most serious complication of AP is multiple system organ failure(MSOF) during the early stage. Mortality from ANP is closely related to thedevelopment of early systemic complications. Several mediators Such as activatedpancreatic enzymes, cytokines, endotoxin, superoxides, and arachidonatemetabolites have been suggested to play an important role in the pathogenesis ofANP, but the mechanisms of ANP still need further study. rhKD/APP from genetic engineering is recombination human β amyloid proteinprecursor fragment(289-345) which is made of 57 amino acid. rhKD/APP hasactivity of the Kunitz of serine protease inhibitors. It is known to inhibit proteolysisof kallikrein, plasmin and trypsin. The role of rhKD/APP has always been considered to be due to the inhibitionof the exocrine pancreatic secretion in order to reduce pancreatic autodigestion andwas deeply investigated. In the meanwhile rhKD/APP can inhibit cytokines andinflammation, it play a therapeutic and preventive role in AP. We use the model of ANP which is induced by injection of sodiumdeoxycholeaye solution into the main pancreatic duct of rats. Amylase and lipaseactivity were assayed and histopathological changes were observed after treatmentwith rhKD/APP. We observe the therapeutic and prevent effect of rhKD/APP onacute pancreatitis in rats. Whereas the role of rhKD/APP in the pathogenesis of APstill need discussion.1.MethodsAP Model preparation: AP model was induced by slow and even infusion of3.5% sodium taurocholate 0.1mg/100g in pancreatic duct, whereas control groupreceived an infusion of physiological saline of the same amount.1.1 The rats was randomized into six groups, control group,AP model group,and AP+rhKD/APP (lower dosage, medium dosage, maximum dosage) group,AP+BPTI group. In addition to sodium taurocholate, ANP+ rhKD/APP groupreceived intravenous infusion of (40000KIU/kg, 80000KIU/kg, 160000KIU/kg)rhKD/APP, AP+BPTI group received intravenous infusion of 40000KIU/kg BPTIafter model. Control and AP group received the same amount of physiological salineinstead, every 8 hours intravenous infusion, continuously 6 times. After model 48hours, detect the change of serum amylase, lipase, NO, TNF-α, SOD, LPO, andamylase, lipase, SOD, LPO in pancreas tissue;the pathology of pancreas isobserved.1.2 The rats was randomized into six groups, control group, AP model group,and AP+rhKD/APP (lower dosage, medium dosage, maximum dosage) group,AP+BPTI group. In addition to sodium taurocholate, ANP+rhKD/APP groupreceived instil of(80000KIU/kg, 160000KIU/kg, 320000KIU/kg)rhKD/APP,AP+BPTI group received instil of(80000KIU/kg ) BPTI after model. Control andAP group received the same amount of physiological saline instead, every day ig,continuously 6 times. After model 24 hours, detect the change of serum amylase,lipase, NO, TNF-α, PGI2 and TXA2, and amylase, lipase in pancreas tissue;thepathology of pancreas is observed.2.Results2.1 Changes of amylase and lipase of serum and tissue: After above treatment,serum amylase and lipase in AP group rose rapidly(P<0.001). Compared with APgroup,serum amylase and lipase of AP+rhKD/APP (lower dosage, medium dosage,maximum dosage) group significantly lower than serum amylase and lipase inAP(p<0.05, p<0.01). The effect of maximum dosage group is about equal to BPITgroup.2.2 Changes of serum TNF and NO: serum TNF and NO in AP group roserapidly (P<0.001). Compared with AP group, serum TNF and NO of AP+rhKD/APP(lower dosage, medium dosage, maximum dosage) group significantly lower thanserum TNF and NO in AP (p<0.05). The effect of maximum dosage group is aboutequal to BPIT group.2.3 Change of LPO and SOD of serum and tissue: LPO of serum and tissue inAP group rose rapidly(P<0.001), SOD of serum and tissue in AP group fall rapidly(P<0.001). Compared with AP group,Serum LPO of AP+rhKD/APP (lowerdosage, medium dosage, maximum dosage) group significantly lower than serumLPO in AP(p<0.05). Serum SOD of AP+rhKD/APP (lower dosage, medium dosage,maximum dosage) group significantly higher than serum SOD in AP(p<0.05). Theeffect of maximum dosage group is about equal to BPIT group.2.4 Morphological change of the pancreatic tissue;In ANP group,bloodyascites, necrotic foci in pancreas, and fat necrosis in mesentery and omentumwas found grossly. Interstitial lobular inflammatory infiltrations were observed inpancreas microscopicaly, as we as diffusive bleeding and piecemeal necrosis. InAP+ rhKD/APP (lower dosage, medium dosage, maximum dosage) group, ascitesand fat necrosis diminished notably compared with those in AP group.Microscopicaly, slight bleeding, mild acinar degeneration and mild structure damageto lobules were observed together with declining inflammatory infiltration.3.CONCLUSIONSWe use the model of ANP which is induced by injection of sodiumdeoxycholeaye solution into the main pancreaticduct of rats. To observe thetherapeutic and prevent effect of rhKD/APP on acute pancreatitis in rats, to draw aconclusion:3.1 rhKD/APP can reduce serum amylase and lipase in AP group rose rapidly.rhKD/APP inhibits the activation of pancreatic enzymes.3.2 rhKD/APP can reduce LPO of serum and tissue in AP group rapidly andrise SOD of serum and tissue.3.3 rhKD/APP can inhibit serum TNF and NO in AP group rapidly. It preventcytokines and the development of AP.3.4 Morphological change of the pancreatic tissue: rhKD/APP canbloodyascites, necrotic foci in pancreas.