银杏叶提取物对肝硬化大鼠门静脉压及肝窦病理变化的影响

目的探讨银杏叶提取物（EGb）对肝硬化大鼠肝窦微循环及门静脉高压的影响。方法25只雄性Wistar大鼠分为3组：正常对照组（5只）,CCl_4组（10只）,EGb治疗组（10只）。肠系膜上静脉插管测定各组大鼠灌注EGb前后门静脉压力;肝组织匀浆中检测丙二醛（MDA）,血管内皮素（ET-1）,血小板活化因子（PAF）,一氧化氮（NO）,构生型一氧化氮合成酶（cNOS）和诱生型一氧化氮合成酶（iNOS）水平;电镜观察各组肝窦微循环特征。结果EGb灌注后CCl4组门静脉压由（8．7±0．8）mm Hg降至（7．4±0．6）mmHg,降低幅度15%,t 4．11,P＜0．01; EGb治疗组与CCl_4组比较,门静脉压、肝组织MDA、ET-1、PAF、NO和iNOS水平显著降低（P＜0．05或P＜0．01）,肝窦内胶原沉积、微血栓形成、肝窦毛细血管化程度减轻。结论银杏叶提取物能改善肝窦微循环障碍,降低门静脉压力,其可能机制是降低MDA、ET 1、PAF含量,下调iNOS的表达调节NO含量,对慢性肝病治疗具有重要意义。

The effect of Ginkgo biloba extract on portal hypertension and hepatic microcirculation in rats

OBJECTIVE: To evaluate the effect of Ginkgo biloba extract (EGb) on hepatic microcirculation and portal hypertension in CCl4 treated rats. METHODS: Twenty-five male Wister rats were divided into a blank, a CCl4 treated and a CCl4 plus EGb treated group, and all were treated for 10 weeks. The free portal vein pressures were measured through catheterizations. Hepatic sinusoidal endothelial cells and other parameters of hepatic microcirculation were studied with transmission electron microscopy. The amounts of malondialdehyde (MDA), endothelin (ET-1), platelet-activating factor (PAF), nitric oxide (NO), cNOS and iNOS in the liver tissues were determined. RESULTS: The portal vein pressure of the CCl4 plus EGb treated group was (7.4 +/- 0.6) mm Hg while the pressure of the CCl4 treated group was (8.7 +/- 0.8) mm Hg. Aggregation of blood cells or microthrombosis in hepatic sinusoids, deposition of collagen in hepatic sinusoids and spaces of Disse, injury of endothelial cells and capillarization of hepatic sinusoid were significantly milder in the EGb group. The amounts of MDA, ET-1, PAF, NO and iNOS were markedly lower in the CCl4 plus EGb treated group than in the CCl4 treated group. CONCLUSION: The results demonstrated that EGb can decrease the portal vein pressure and improve hepatic microcirculation in CCl4 treated rats. The mechanisms of this effect may involve its inhibition on ET-1, PAF, lipid peroxidation, and down regulation of the hepatic iNOS and NO expressions.