甘草酸二铵对百草枯中毒致急性肺损伤大鼠TLR-4表达的影响

目的探讨甘草酸二铵(DG)对百草枯(PQ)中毒致急性肺损伤(ALI)大鼠的保护作用及其机制。方法选择健康SD大鼠50只,随机分为百草枯组(PQ组)、甘草酸二铵组(DG组)和正常对照组(NS组),PQ组和DG组予百草枯100mg/kg灌胃1次,DG组于灌胃后立即腹腔注射DG 50mg/kg,每日1次,对照组与PQ组注射等剂量的生理盐水。观察至48h处死大鼠,取肺组织检测肺湿干重比;肺组织HE染色评价肺组织损伤情况;采用RT-PCR法检测肺组织TLR-4mRNA和NF-κB mRNA的表达情况。另选择健康SD大鼠50只,分组及各组处置方法同上,观察其7天内死亡率。结果 PQ组与DG组肺湿干比、肺组织TLR-4mRNA和NF-κB mRNA表达较NS组明显升高(P0.01);DG组各指标明显低于PQ组(P0.01)。HE染色结果,NS组肺部结构正常,PQ组、DG组可见肺组织水肿、出血及炎性细胞浸润等肺损伤表现,DG组病变轻于PQ组。群体死亡率比较,PQ组7天死亡率为90%,DG组为40%,NS组无死亡。结论甘草酸二铵可减轻百草枯中毒致急性肺损伤大鼠肺部炎症,其机制可能与降低TLR-4、NF-κB的表达有关。

Effects of diammonium glycyrrhizinate on the expression of Toll-like receptor 4 in rat lung with acute lung injury induced by Paraquat

Objective To evaluate the effect of Diammonium Glycyrrhizinate（DG） on Paraquat induced acute lung injury in rats. Methods Fifty SD rats were randomly divided into control group（NS） ,PQ group and DG group. The rats in PQ group and DG group were intragastriced administration with paraquat （100 mg/kg）. The rats in DG group were intragastriced administration with DG （50 mg/kg） once per day after paraquat injection. The NS group and PQ group were injected of same amount of saline,observed the 7 day mortality rate;another 50 healthy SD rats were cheesed,and Disposalibid, were killed at 48 hours. Detection of arterial blood oxygen partial pressure;detected of pulmonary lung wet to dry weight ratio;the lung tissue HE staining to evaluate the pulmonary tissue injury; to detect the expression of lung tissue TLR-4 mRNA,NF-xB mRNA using RT-PCR method. Results Population mortality results：PQ group of 7 day mortality was 90 %, 40 % in DG group,and no death in NS group;Compared with the control group,the lung tissue＇s wet/dry weight ratio,expression of lung tissue TLR-4 mRNA and NF-κB mRNA increased significantly of the PQ group and DG group （P〈0.01）. The each index of DG group were much lower than those of PQ group （P〈0.01）. DG group was lower than that of NS group in HE staining：NS group lung structure was normal. There was pulmonary edematous, hemorrhage and inflammatory cell infiltration in lung injury of PQ group and DG group. And the DG group lesions lighter than that of PQ group. Conclusion Diam- monium glycyrrhizinate can attenuate the acute lung injury induced by paraquat poisoning in rats,the mechanism may be related to the decrease of TLR-4,NF-κB expression.