对酚妥拉明降低肺动脉高压作用机制的探讨

应用大鼠离体肺动脉环标本，采用累积量效曲线方法．观察到应用野百合碱致肺动脉高压的大鼠离休肺动脉环对去甲肾上腺素、肾上腺素的反应性明显增强．其累积量效曲线较正常组明显平行左移．两组－ｌｇＥＣ５０差值经ｔ检验Ｐ＜０．０１；应用野百合碱致肺动脉高压．同时加用酚妥拉明预防治疗的大鼠离休肺动脉环对去甲肾上腺素、肾上腺素的反应性下降，其累积量效曲线较野百合碱组明显平行右移，两组间－ｌｇＥＣ５０差值经ｔ检验Ｐ＜０．０１．这些结果提示野百合碱引起的肺动脉高压可能与肺动脉血管壁对内源性儿茶酚胺类物质－去甲肾上腺素、肾上腺素的敏感性增强有关，而酚妥拉明降低肺动脉高压与肺动脉血管壁对内源性儿茶酚胺类物质的反应性降低有关。

Investigation of mechanism of Phentolamine in Lowering Pulmonary Arterial Hypertention

In isolated pulmonary arterialrings of guinea pigs,the reactivity to NE and ADof isolated pulmonary rings of pulmonary arterial hypertension induced by MCT obviously increased.The cumulative concentration-responsecurve caused by NE and AD parallelly shifted toleft in MCT group.The difference of-lgEC50between MCT group and normal group significant(P<0.05).The reactivity to NE andAD of isolated pulmonary arterial rings of preventing and treating group obviously decreased.The cumulative concentration-responese curvecaused by NE and AD paiallelly Shiftod to rightin preventing and treating gruop.The differenceOf lgEC50 between MCT group and normal groupwas significant(P<0.01).These results suggest that pulmonary arterial hypertension induced by MCT relates to hypersensitivity of vascular wall to intergenic catecholamines and that the lowering effect of phentolamine on pulmonary arterial hypertensionnelates to its seducing reactivity of vascular wallto intergenic catecholamine.