银杏叶提取物对大鼠肺缺血-再灌注损伤的保护作用

目的探讨银杏叶提取物对肺缺血一再灌注（I／R）损伤保护作用的机制。方法36只SD大鼠随机等分为假手术对照（S组）组、缺血一再灌注（I／R）组、银杏叶提取物＋缺血／再灌注（EGB＋I／R）组。观察大鼠单侧肺缺血1小时再灌注1h后肺组织NF-KB的表达变化，肺细胞凋亡、超微结构损伤情况。结果①I／R组NF-KB的10D值显著增加，高于S组，而EGb＋I／R组NF_KB的10D值较I／R组减少。②缺血一再灌注后I／R组凋亡的AI数显著增加，高于S组，而EG昏I／R组凋亡的AI数较I／R组减少。③电镜下I／R组肺泡毛细血管内皮细胞、Ⅰ型肺泡上皮细胞水肿变性，Ⅱ型肺泡上皮细胞膜微绒毛减少；EGb＋I／R组Ⅱ型肺泡上皮细胞表面微绒毛增多。结论银杏叶提取物对肺再灌注所致肺细胞凋亡有保护作用，对缺血再灌注后超微结构损伤有一定改善作用，其机制可能与降低NF-KB的活化有关。

The protective efects of EGb against lung ischemia reperfusion injury in rats

Objective To study the protective effects of ginkgo leaf extract agents against lung ischemia/reperfu- sion injury. Methods Thirty six Sprague Dawley rats used for unilateral lung ischemia/reperfusion modelwere randomly divided into three groups .. sham operation group （Sgroup, n = 12）, ischemia/reperfusion group （ I/R group, n =12）, and ginkgo leaf exact agents with ischemia/reperfusion group（（EGB＋ I/R group, n= 12）. The unilateral rat lung ischemia 1 hour after lh of reperfusion, expression of NF KB changes in lung and cell apoptosis and ultrastructural damage were ab-served. Results The expression of NF KB in lung was obviously higher in I/R group than which in S group（P〈0.05）. while in EGb ＋ I/R group ,the expression of NF-KB in lung decreased than which in I/R group （P〈0.05）; After Ischemia reperfusion, apoptosis-positive cells of I / R group increased significantly and reduced in EGB-I/R group thanwhich of I/R group （P〈0.05）. Electron microscope, I/R group ; The alveolar capillary endothelial cells and Ⅰtype alveolar epithelial cells degenerated and became bloated, reduced microvilli on the surface of type Ⅱ alveolar with swollen mitochondria; EGb ＋I/R group： Microvilli on the surface of Ⅱ type alveolar epithelial cell increased. Conclusion Ginkgo leaf extract agent can attenuate the apoptosis of lung cells and the change of ultrastructure induced by ischemia/reperfusion injury of lung to some extent. Its mechanism may be related to a reduction in the activation of NF KB.