卡巴胆碱对烫伤大鼠口服补液时小肠TNF-α及水通道蛋白-1的影响

Effect of carbachol on expression of TNF-α and aquaporin-1 in small intestine during enteral resuscitation of scald injury in rats

目的:研究拟胆碱药卡巴胆碱对烫伤大鼠口服补液时小肠TNF-α及水通道蛋白-1(AQP-1)表达的影响.方法:♂Wistar大鼠50只,随机分为假烫(N)、单纯烫伤(S)、肠内葡萄糖-电解质液(GES)、肠内卡巴胆碱组(CAR)和肠内葡萄糖-电解质液+卡巴胆碱组(GES/CAR)5组(n=10).大鼠背部用沸水造成35%TBSA烫伤.N,GES和GES/CAR组于伤后30min开始补液.免疫组化法测定肠组织AQP-1的表达,ELISA法检测肠组织TNF-α含量,酚红法测定大鼠小肠对水的吸收率.结果:S组大鼠小肠AQP-1与N组比明显降低(90.3±18.4vs4851.6±654.5,P<0.01);CAR,GES和GES/CAR组AQP-1与S组相比均显著增加(1806.1±110.1,2272.3±113.8,3322.0±595.9vs90.3±18.4,均P<0.01).给予卡巴胆碱组(CAR,GES/CAR)与未给予卡巴胆碱组(S,GES)相比肠组织TNF-α含量明显下降(0.9±0.3,1.0±0.47vs1.8±0.3,1.9±0.2,P<0.05).GES/CAR,CAR及S组AQP-1表达量与TNF-α含量成负相关(r=-0.9030,-0.9602,-0.9866,均P<0.05).GES/CAR组水吸收率较GES组明显升高(21.0%±0.1%vs12.7%±0.1%,P<0.05).结论:卡巴胆碱可抑制促炎因子TNF-α的释放,上调小肠AQP-1表达,改善大鼠烫伤早期肠道对水的吸收.

AIM： To investigate the effects of carbachol （a cholinergic agent） on expression of tumor necrosis factor-α （TNF-α） and aquaporin-1 （AQP-1） water channels in small intestine of scalded rats. METHODS： Wistar rats were randomly assigned to five groups： shame scald （N）, scald without fluid resuscitation （S）, scald resuscitated with enteral GES alone （GES）, scald resuscitated with enteral carbachol alone （CAR） and scald resuscitated with enteral carbachol plus GES （GES/ CAR） （n = 10）. About 35% TBSA of scald injury was formed with boiling water on back of rats in all groups except the shame scald group. N, GES and GES/CAR groups were enterally administered 30 min after scald injury. The specimens of jejunum of all groups were harvested and analyzed. AQP-1 expression in intestines was evaluated using immunohistochemical method, TNF-α was measured using ELISA and the liquid absorption rate was determined using phenol red. RESULTS： Compared with the shame scald group, AQP-1 expression in small intestine was significantly decreased in scalded animals （90.3 ± 18.4 vs 4851.6 ± 654.5, P 〈 0.01）, but significantly increased in CAR, GES and GES/CAR groups （1806.1 ± 110.1, 2272.3 ± 113.8, 3322.0 ± 595.9 vs 90.3 ± 18.4, all P 〈 0.01）. TNF-α level in intestinal tissues of GES/CAR and CAR groups were markedly suppressed compared with those in S and GES groups （0.9 ± 0.3, 1.0 ± 0.47 vs 1.8 ± 0.3, 1.9 ± 0.2, P 〈 0.05）. TNF-α expression level was negatively correlated with AQP-1 of small intestine in GES/CAR, CAR and S groups （r = -0.9030, -0.9602, -0.9866, all P 〈 0.05）. Liquid absorption rate of small intestine in GES/CAR group was significantly increased compared with GES group （21.0% ± 0.1% vs 12.7% ± 0.1%, P 〈 0.05）. CONCLUSION： Carbachol have significant effects on improving the liquid absorption by inhibiting TNF-α and up-regulating AQP-1 expression in small intestine.