甘草酸二铵对百草枯中毒大鼠肾组织TOLL样受体4表达的影响

摘要

目的 了解甘草酸二铵(DG)对百草枯(PQ)中毒大鼠肾组织TOLL样受体4(TLR4)及NF-κB等表达影响.方法 根据随机数字表法将大鼠分为PQ染毒组(PQ组,n=20)、DG干预组(DG组,n=20)和空白对照组(NS组,n=10).PQ组及DG组100 mg/kg一次性灌胃方式建立急性肾损伤大鼠动物模型,NS组予以等量生理盐水灌胃,DG组灌胃后立即给予甘草酸二铵50 mg/kg腹腔注射,每24 h重复给药一次.ELISA检测血清和肾组织IL-6、IL-10的含量,免疫组化分析各组TLR4、Myd88及NF-κB P65蛋白表达变化,荧光定量PCR方法检测肾组织TLR4、Myd88及NF-κB的的基因表达.结果 与NS组比较,PQ组的血肌酐(Cr)、尿素氮(BUN)、血清及肾组织中IL-6水平均明显升高(F=266.014,168.160,63.279, 192.997,均P＜0.01).与PQ组比较,DG组Cr、BUN、血清及肾组织中IL-6水平均明显降低(F=266.014,168.160,63.279, 192.997,均P＜0.01).与NS组比较,PQ组的肾组织和血清中IL-10水平均明显升高(F=87.511,79.473,均P＜0.01),与PQ组比较,DG组的肾组织和血清中IL-10水平均有一定升高(F=87.511,79.473,均P＜0.01).与NS组比较,PQ组肾组织TLR-4、Myd88及NF-κBmRNA表达明显升高(F=84.408,60.683,86.272,均P＜0.01);与PQ组比较,DG组肾组织TLR-4、Myd88及NF-κB mRNA表达明显降低(F=84.408,60.683,86.272,均P＜0.01).免疫组化结果显示,PQ组肾组织TLR-4、Myd88及NF-κB的蛋白表达量明显升高(F=79.139,61.799, 112.740,均P＜0.01).与PQ组比较,DG组肾组织TLR-4、Myd88和NF-κB的蛋白表达量明显降低(F=79.139,61.799,112.740,均P＜0.01).结论 甘草酸二铵可减轻百草枯中毒大鼠的急性肾损伤,并能降低肾组织TLR-4、myd88及NF-κB的表达水平.%Objective To investigate the effects of diammonium glycyrrhizinate (DG) on the expression of Toll-like receptor 4 in rat' s kidney poisoned by paraquat (PQ).Methods The PQ (100 mg/kg) were administered via a gastric tube to make an animal model of acute kidney injury in rats.Then DG (50 mg/kg per 24 h) were administered immediately by intraperitoneal injection in the DG group.The ELISA assay was applied to measuring the IL-6 and IL-10 in kidneys and in blood.And the protein expressions of TLR-4, Myd88 and NF-κB P65 were examined by Immunohistochemistry.The gene expressions of TLR-4, Myd88 and NF-κB on kidneys were detected by RT-PCR.Results The levels of serum Cr, BUN , IL-6 and renal IL-6 in PQ group were significantly higher than those in NS group (F =266.014, 168.160, 63.279, 192.997, respectively, P ＜0.01).While, the levels of serum Cr, BUN , IL-6 and renal IL-6 in DG group were significantly lower than those in PQ group (F =266.014, 168.160, 63.279, 192.997, respectively, P ＜ 0.01).And the levels of serum and renal IL-10 in PQ group were higher than those in NS group (F =87.511, 79.473, respectively, P ＜ 0.01).But the levels of serum and renal IL-10 in DG group were lower than those in PQ group (F =87.511, 79.473, respectively, P ＜0.01).The results of PCR confirmed that the expressions of TLR-4 mRNA , myd88 mRNA and NF-κB mRNA in PQ group were higher than those in NS group (F =84.408, 60.683, 86.272, respectively, P ＜0.01), while, the expressions of TLR-4 mRNA , myd88 mRNA and NF-κB mRNA in DG group were lower than those in PQ group (F =84.408, 60.683, 86.272, respectively, P ＜ 0.01).The protein levels of TLR-4 , Myd88 and NF-κB P65 in PQ group were higher than those in NS group (F =79.139, 61.799,112.740, respectively, P ＜0.01).While the protein levels of TLR-4, Myd88 and NF-κB P65 in DG group were lower than those in PQ group (F =79.139, 61.799, 112.740, respectively, P ＜ 0.01).Conclusions Diammonium Glycyrrhizinate can attenuate rat's acute kidney injury caused by paraquat poisoning and decrease the expressions of TLR-4, Myd88 and NF-κB.