Expression of pancreatic thioredoxin-1 in rats with acute necrotizing pancreatitis and effect of melatonin on thioredoxin-1 / 中华胰腺病杂志

ABSTRACT

Objective To investigate the expression of pancreatic thioredoxin-1 (TRX-1) in rats with acute necrotizing pancreatitis (ANP) and the effect of pretreatment of melatonin on its expression. Methods Male Spraque-Dawley rats (n = 12) were randomly divided to ANP group, melatonin group, control group with 24 rats in each group. The rats in ANP group received three intraperitoneal injections of 25 ml/kg body weight 6% L-arginine at an interval of 1 h to induce ANP. The rats in melatonin group received intraperitoneal injections of 25 ml/kg body weight 6% melatonin 30 min before ANP induction; rats in ANP group and control group received intraperitoneal injections of same amount of saline. Rats were sacrificed at 6 h, 12 h and 24 h after ANP induction. The serum level of amylase was measured and the pathological evaluation of pancreatic tissues was performed. The concentrations of malondialdehyde (MDA) and myeloperoxidase (MPO) in pancreatic tissues were measured. The expressions of TRX-1 protein were detected by immunohistochemistry and the expressions of TRX-1 mRNA in pancreatic tissues were determined by RT-PCR.Results In ANP group, serum level of amylase, MDA, MPO, TRX-1 mRNA and TRX-1 protein in pancreatic tissues were (3 012 ±1 425) U/L, (4.13 ± 1. 85)nmol/mg prot,(7.45 ± 1.26)nmol/mg prot, 0.68 ±0. 18, 66.8 ±8. 1, while they were (1 835±499)U/L, (3.03 ±2.12) nmol/mg prot, (5. 32 ± 1.06) nmol/mg prot, 0.50±0.09, 80. 29 ±8. 14, respectively in melatonin group, the values in melatonin group were significantly lower thanthose in ANP group (P < 0.05). The peak value of TRX-1 mRNA and TRX-1 protwein expressions shifted from 12 h after ANP induction in ANP group to 6 h after ANP induction in melatonin group. Conclusions The expression of pancreatic TRX-1 protein and TRX-1 mRNA in rats with ANP was significantly increased. Melatonin pretreatment could promote pancreatic tissues to express TRX-1 protein and TRX-1 mRNA, and may be protective for pancreatic tissues damages.