N-乙酰半胱氨酸拮抗丙烯酰胺的肝肾毒性及机制

The antagonistic effect and mechanism of N-acetylcysteine on acrylamide-induced hepatic and renaltoxicity

目的探讨丙烯酰胺（ACR）的肝肾毒性作用以及N-乙酰半胱氨酸（NAC）对ACR肝肾毒性的拮抗作用及机制。方法40只雌性SD大鼠随机分为对照组（腹腔注射生理盐水，1．5h后生理盐水灌胃）、NAc组（腹腔注射200m非异NAC，1．5h后生理盐水灌胃）、ACR组（腹腔注射生理盐水，1．5h后40mg/kgACR灌胃）和联合处理组（腹腔注射200mg/kgNAC，1．5h后40mg/kg ACR灌胃），每天染毒1次，共染毒2周。末次染毒24h后断头处死大鼠，收集血液，分离肝脏和肾脏，分别测定各组大鼠体重、脏器系数、血清生化指标，组织病理检查和检测（NF-KBp65、IKB-α及cox-2）的表达。结果从染毒第2天到染毒结束，ACR组的体重持续低于对照组，差异有统计学意义（P〈0．05）；与联合处理组比较，染毒第2、3天ACR组体重降低，差异有统计学意义（P〈0．05）。ACR组肝和肾脏器系数分别为（4．159％±0．371％）和（0．764％±0．068％），明显高于对照组，差异有统计学意义（P〈O．05）。ACR组血清中ALT、AST和Cr含量分别为（77．370±16．397）U/L、（379．410±57．817）U/L和（77．812±6．391）μmol/L，与对照组及联合处理组比较，差异均无统计学意义（P〉0．05）；ACR组血清中BUN含量为（7．005±1．009）mmol／L，明显高于对照组，差异有统计学意义（P〈0．05）。组织病理切片显示，ACR组肝细胞界限不清，胞核固缩，肝索结构疏松、排列紊乱，各组肾脏无明显病理改变。westem blot结果表明，ACR组肝脏中核NF．KBp65和COX-2的表达高于对照组和联合处理组，IKB-α的表达低于对照组和联合处理组，差异均有统计学意义（P〈0．05）；ACR组肝脏中总NF-KBp65的表达高于对照组，差异有统计学意义（P〈0．05）。结论在该实验条件下，ACR可能通过激活NF-KB信号通路对肝脏产生毒性作用，且NAC可能通过抑制NF-KB信号通路来拮抗ACR的肝毒性，而ACR对肾脏的毒性作用有待进一步研究。

Objective The aim of this study is to investigate hepatic and renal toxicity of acrylamide （ACR）, the antagonistic effect and possible mechanism of N-acetylcysteine （NAC） on the toxicity. Methods Forty female SD rats were randomly divided into four groups. All the rats were administrated by intraperitoneal（i. p.） injection and 1.5 hours later by gavage. The controlgroup was administrated with 0.9% NaC1 by i.p. injection and gavaged with 0.9% NaC1. The NAC group was administrated with 200 mg/kg NAC by injection and gavaged with 0.9% NaC1. The ACR group was administrated with 0.9% NaC1 by injection and gavaged with 40 mg/kg ACR. The combined treatment group was administrated with 200 mg/kg NAC by i.p. injection and gavaged with 40 mg/kg ACR. The rats were administrated once a day for 2 weeks. After 24 hours of the last administration, the rats were decapitated. The blood was collected, the l^ver and kidney were separated. The body weight, organ coefficient and serum biochemical parameters were measured, and the pathological changes of the tissues were examined with a microscope. Then the expression of NF-KB p65, IKB-et and COX-2 were detected by Western blot. Results From the second day to the end of the exposure, the body weight of rats in the ACR group was statistically lower than that in the control group （P〈0.05）. Compared with the combined treatment group, the body weight in the ACR group statistically decreased in the second and third days （P 〈 0.05）. The liver and kidney organ coefficients in the ACR group were （4.159%±371%） and （0.764%±0.068%） respectively, which increased statistically when compared with the control group （P 〈 0.05 ）. The contents of ALT, AST and Cr in the serum in the ACR group were（77.370±16.397） U/L, （379.410±57.817） U/L and （77.812±6.391） μmol/L respectively, which were not significantly different with those in the control group and the combined treatment group （P〉0.05）. The content of BUN in the serum in the ACR group was （7.005±1.009） mmol/L, which was statistically higher than that in the control group （P〈0.05）. Histopathology results showed unclear boundary and nucleus pyknosis in hepatocytes, loose and disordered structures of hepatic cords in the ACR group, but no obvious pathology changes were observed in the kidneys of each group. In the Western blot results, the expression of nuclear NF-KB p65 and COX-2 in the liver in the ACR group was statistically higher than that in the control group and the combined treatment group （P〈0.05）, and the expression of IKB-c~ in the liver in the ACR group statistically decreased compared with the control group and the combined treatment group （P〈0.05）. The expression of total NF-KB p65 in the liver in the ACR group was statistically higher than that in the control group（P〈O.05）. Conclusion Under the conditions of this experiment, ACR may induce hepatic toxicity through the activation of NF-KB signaling pathway, and NAC could antagonize the hepatic toxicity of ACR by inhibiting the NF-KB signaling pathway, whereas the toxic effect of ACR on kidney needs to be further studied.