RESUMO
Objective:To evaluate the effect of dexmedetomidine on the thioredoxin-interacting protein (TXNIP)/apoptosis signal-regulated kinase 1 (ASK1) signaling pathway in a mouse model of intestinal ischemia-reperfusion (I/R).Methods:Thirty-two SPF healthy adult male C57BL/6J mice, aged 8-10 weeks, weighing 18-22 g, were divided into 4 groups ( n=8 each) using a random number table method: sham operation group (Sham group), intestinal I/R group (I/R group), TXNIP inhibitor resveratrol group (Res group) and dexmedetomidine group (Dex group). The mouse model of intestinal I/R injury was developed by clamping the superior mesenteric artery for 45 min followed by 120-min reperfusion in anesthetized animals. Resveratrol 30 mg/kg was intraperitoneally injected before developing the model in Res group, and dexmedetomidine 25 μg/kg was intraperitoneally injected at 30 min before ischemia in Dex group. Blood samples were collected by cardiac puncture at the end of 120-min reperfusion, then the mice were sacrificed, and the small intestine tissues were removed for microscopic examination and for determination of the serum diamine oxidase (DAO) concentration (by enzyme-linked immunosorbent assay) and expression of TXNIP, ASK1 and cleaved-caspase-3 in small intestinal tissues (by Western blot). The apoptosis rate of intestinal epithelial cells was calculated. The intestinal damage was assessed and scored according to Chiu. Results:Compared with group Sham, the Chiu′s score, serum DAO concentrations and apoptosis rate of intestinal epithelial cells were significantly increased, and the expression of TXNIP, ASK-1 and cleaved-caspase-3 was up-regulated in group I/R ( P<0.05). Compared with group I/R, the Chiu′s score, serum DAO concentration and apoptosis rate of intestinal epithelial cells were significantly decreased, and the expression of TXNIP, ASK-1 and cleaved-caspase-3 was down-regulated in group Res ( P<0.05). Compared with I/R group, the Chiu′s score, serum DAO concentration and apoptosis rate of intestinal epithelial cells were significantly decreased, and the expression of TXNIP, ASK-1 and cleaved-caspase-3 was down-regulated in Dex group ( P<0.05). Conclusions:The mechanism by which dexmedetomidine alleviates intestinal I/R injury may be related to inhibition of the TXNIP/ASK1 signaling pathway and reduction of cell apoptosis in mice.