青天葵对内毒素致急性肺损伤大鼠肺水通道蛋白1和5表达的影响

Effect of Nervilia fordii on Lung Aquaporin 1 and 5 Expression in Endotoxin-induced Acute Lung Injury Rat

目的通过观察青天葵预先给药对内毒素致急性肺损伤(acute lung injury,ALI)大鼠肺水通道蛋白1和5(aquaporin 1 and 5,AQP-1、AQP-5)表达的影响,探讨其保护作用机制。方法 SD大鼠24只随机分为正常组(A组)、青天葵预保护组(B组)、内毒素模型组(C组)。B、C组采用舌底静脉注射内毒素(5mg/kg)复制ALI模型,B组预先给予10mL/kg青天葵水煎液及每天灌胃处理,造模8h后检测3组肺湿/干重比(W/D),观察肺脏水通透性的变化,HE染色观察肺组织病理学的改变,免疫组化法及逆转录多聚酶链反应(RT-PCR)法检测AQP-1、AQP-5在肺内的表达。结果与C组比较,B组及A组肺W/D比值明显降低(P<0.05),B组肺水肿病理改变程度明显减轻,AQP-1、AQP-5在肺内的蛋白表达水平升高(P<0.05)。结论青天葵预先给药可通过促进ALI大鼠肺AQP-1和AQP-5的表达上调,增加清除和转运肺水,改善水液代谢,减轻肺水肿状态,从而有效保护急性肺损伤。

Objective To explore the protective mechanism of Nervilia fordii （NF） by observing the effect of its pretreatment on lung aquaporin 1 and 5 （AQP-1, AQP-5） expression in rats with endotoxin-induced acute lung injury （ALl）. Methods Twenty-four SD rats were randomly divided into 3 groups, the normal group （A）, the NF pre-intervention group （B） and the endotoxin model group （C）. Rats in Group B and C were made into ALl by endotoxin （5 mg/kg） injection via sublingual vein, and NF pretreatment was applied to Group B. Animals were sacrificed at the 8 h after modeling, their lung were taken for observing the water permeability change by wet/dry weight ratio （W/D） measuring, pathological feature by HE staining, and the expression of AQP-1, AQP-5 was detected by immunohistochemistry and RT-PCR. Results The W/D ratio of lung was higher in model rats than in normal rats, but as compared with Group C, it was significantly lower （ P 〈0.05） in Group B. The pulmonary edematous change was significantly mild and the AQP-1 and AQP-5 protein expressions were signifi- cantly higher in Group B than in Group C （ P 〈0.05）. Conclusion NF pretreatment can promote lung AQP-1 and AQP-5 expression up-regulation, increase lung water clearance and transportation to improve the water balance and eliminate pulmonary edema, so as to effectively protect lung from acute injury.