Expression Of Thioredoxin-1 In Rats With Experimental Acute Necrotizing Pancreatitis And Effect Of Melatonin Intervention

THE FIRST PART OF THESISEXPRESSION OF THIOREDOXIN-1 IN RATS WITH EXPERIMENTAL ACUTE NECROTIZING PANCREATITISObjective To investigate the expressions of thioredoxin-1 (Trx-1)and Trx-1mRNA in serum and(or) pancreas in rats with experimental acute necrotizing pancreatitis (ANP) .Methods Male Spraque-Dawley rats (48) were randomly allocated to two group . Those in ANP group received three injections of 25ml/ kg body weight 6%L-arginine i.p. at an interval of 1 h to induce ANP and one time injections of 20ml/ kg body weight physiological saline i.p at half hour before the first L-arginine injection and after the last L-arginine injection, respectively. In control group, rats served as control animals and received i.p injections of physiological saline. The rats were sacrificed at the 6h,12h and 24h after the last L-arginine injection. The pancreas and blood were quickly removed and stored as samples. The pathologic changes of pancreatic tissues were observed and The histopathological scores of pancreatic tissues were calculated. The concentrations of amylase and Trx-1 in serum were measured. The expressions of Trx-1 and Trx-1mRNA in pancreatic tissues were confirmed by immunohistochemistry and RT-PCR, respectively.Results The acute necrotizing pancreatitis in ANP group was confirmed by the pathologic changes and the histopathological scores of pancreatic tissues and the concentration of serum amylase. Compared to content at same time point in control group, the content of serum Trx-1 was significantly decreased at 6h,12h points and significantly increased at 24h points in ANP group.The levels of serum Trx-1 in rats with ANP showed the trend of Trx-1 concentration decrease at the beginning then increase gradually, and reached the peak value at 24h point.The levels of expressions of Trx-1 and Trx-1mRNA in pancreatic tissues in ANP group were significantly higher than those in the control group and reach peak value at 12h point.Conclusions In rats with ANP , Trx-1 levels in serum showed a trend which is decrease at the beginning then increase gradually with time, which suggests the Trx-1 level can be used as a dynamic indicator for the evaluation of Acute Pancreatitis severity in relation to oxidative stress.The expressions of pancreatic Trx-1 and Trx-1mRNA was remarkablely high, which reflects the body's self-protection mechanism, suggesting that exogenous Trx-1 may contribute to pancreatic tissue response to oxidative stress.