检测内皮素(endothelin，ET)受体在小儿左向右分流先心病肺循环中的表达，并分析其与先心病肺血管重构的关系。

按超声所测Q_p/Q_s和RPEP/VTI将23例左向右分流先心病患儿分组。通过免疫组化和图像分析，测定受体在肺小血管的IOD值。同时运用组织病理及体视学方法，检测肺循环小血管的WT%，血管密度及VSMC的PCNA细胞阳性率和α-actin血管阳性率。

介导ET-1功能的两种受体ETA，ETB表达在各观察组较对照组有显著增高(P<0.01)，两种受体表达与反映肺血管重构的指标呈不同程度的相关。

体视学及病理学方法对肺动脉高压早期肺血管重构的评价，较Health-Edwards病理分级更为敏感。内皮素受体表达的变化，提示ET促使先心病肺血管重构的效应除了与ET的促增殖作用本身有关外，血流动力学因素导致ET受体上调可能也起到了重要作用。

To investigate the expression and distribution of endothelin receptors in pulmonary circulation in children with congenital left-to-right shunts and to explore their correlations with histopathological changes in pulmonary vasculature.

23 children with congenital left-to-right shunts were divided into 3 groups according to the echocardiographic Q_p/Q_s and RPEP/VTI(right ventricular pre-ejection period/velocity time integral which may characterize the difference in pulmonary resistance).Integral optical density(IOD)of receptors in pulmonary circulation was measured by immunohistochemical stain of receptors.Stereologic and histopathologic methods were used to measure parameters including PCNA, WT%(percent wall thickness)and density of vasculature and the distribution of α-actin positive cells, so as to assess the vascular remodeling of pulmonary circulation.

Expression of two endothelin receptor subtypes were both higher on small pulmonary arteries in cases than in control cases(P<0.01).Expression of both subtypes correlated basically well with the stereologic and pathological parameters of remodeling of small pulmonary arteries.

Stereologic assay is more sensitive than Health-Edwards criteria in evaluating the vascular remodeling in early pulmonary hypertension induced by congenital left-to-right shunts.The changes of ET receptor expression in small PA implicate that important role of ET in pulmonary hypertension may also correlate with the up-modulating of ET receptors due to change in flow dynamics.