肝肺综合征大鼠肺组织内皮素-1及其受体基因的表达

Expression of Pulmonary ET-1 and its Receptors in Rats of Hepatopulmonary Syndrome

目的探讨内皮素-1及其受体在大鼠肝肺综合征(HPS)发病机制中的作用。方法分别采用RT-PCR和原位杂交方法检测HPS大鼠肺组织内皮素前体原(ppET-1)mRNA水平及两种亚型内皮素-1(ET-1)受体ETRA和ETRB在HPS大鼠肺组织的分布和表达。结果HPS大鼠肺组织ppET-1mRNA表达显著升高(0.48±0.06),为假手术(Sham)组表达量(0.21±0.04)的2.3倍(t=2.4114,P<0.05)。HPS大鼠肺血管ETRA的分布及染色强度与Sham组比较无明显变化,染色面积和平均积分光密度值与Sham组比较差异无统计学意义(P>0.05),而ETRB在远端肺小动脉和小静脉内膜上表达明显增强,尤以静脉明显。ETRB染色面积和平均积分光密度值明显高于Sham组(P<0.001)。结论HPS大鼠肺组织ET-1基因表达水平升高。ET-1在HPS大鼠肺血管的总体反应可能由于ETRB表达的增高而表现为扩张。

Objectives To investigate the role of ET-1 and its receptors in the machanism of hepatopulmonary syndrome in rats. Methods The level of lung ppET-1 mRNA was determined by RT-PCR,and the distribution and expression of two kinds of subtype receptor of ET-1, ETRA and ETRB were evaluated by in situ hybridazation. Results The level of lung ppET-1 mRNA in HPS group was 2.3 folds higher than that in Sham group（0.48±0.06 vs 0.21±0.04, P 〈 0.05 ）. No distinct alteration of the distribution and the staining intensity of ETRA in pulmonary vascular was seen between HPS group and Sham group, but significant enhancement of ETRB staining in endothelium of distal small vascular were observed,especially in small veins. There was no difference of the ETRA staining area and average optical density between two groups（ P 〉 0.05 ） , while that of ETRB was higher than control （ P 〈 0.01 ）. Conclusion Expression of ET-1 increased in lung of HPS rats, the dilatation of the pulmonary vascular may be the final of ET-1 because of the increasing expression of ETRB.