杏花雨对外源性高钙致大鼠脑线粒体损伤的保护作用

目的探讨杏花雨注射液对外源性高钙所致线粒体损伤的保护作用.观察杏花雨对离体线粒体是否具有保护作用,从而进一步完善银杏叶提取物抗脑缺血损伤的机制.方法新鲜制备的大鼠脑线粒体悬液,分别与不同浓度Ca2 以及不同浓度的杏花雨注射液进行孵育,观察线粒体基质游离钙、线粒体活性以及线粒体膜肿胀度的变化.结果与正常对照组比较外源性高钙导致大鼠脑线粒体严重钙超载(P＜0.01),线粒体活性下降(P＜0.01),540 nm处线粒体悬液吸光度值显著下降,线粒体明显肿胀(P＜0.01);于钙离子损伤前给予杏花雨孵育,线粒体基质游离钙浓度明显降低(P＜0.01),线粒体活性显著升高(P＜0.01),吸光度值有明显升高,显示线粒体肿胀度减轻(P＜0.01).结论外源性高钙可使线粒体基质游离钙含量升高,产生线粒体通透性转换(mitochondria permeability transition,MPT),使线粒体活性降低,功能障碍.杏花雨通过缓解线粒体钙超载,防止产生MPT,从而恢复线粒体功能.提示杏花雨抑制线粒体钙超载可能是其对缺血再灌注脑损伤的保护作用机制.

The protective effect of Xinhani injection against cerebral mitochondria damage caused by exogenous Ca2+

Objective To observe the protective effect of Xinhani against mitochondria injury induced by exogenous Ca~(2+).Methods Isolated mitochondria was prepared from brain of rats.The concentration of free Ca~(2+) in mitochondria,the activity of mitochondria and MPT were measured respectively in the presence of Ca~(2+) at different concentration without or with Xinhani.The swelling of mitochondria represented by OD values at 540 nm.Results AS compared with that of control group,Ca~(2+) concentration of mitochondria was increased significantly(P<0.05 or P<0.01) respectively when incubated with CaCl_2,decreased the activity of mitochondria(P<0.01),MPT induce swelling of mitochondria and OD values at 540 nm of mitochondria suspension decreased.OD values at 540 nm of mitochondria suspension could manifest the change of swelling of mitochondria(P<0.01);Xinhani reduced significantly Mca increase induced by CaCl_2(P<0.01),and reduced the activity of mitochondria(P<0.05 or P<0.01),OD values at 540 nm of mitochondria suspension were increased by Xinhani(P<0.05 or P<0.01).Conclusion Exogenous Ca~(2+) could increase the concentration free Ca~(2+) in mitochondria,leaded to opening of MPT and decrease the activities of mitochondria.Xinhani could protect mitochondria from damage induced by exogenous Ca~(2+).The protection effect of Xinhani on mitochondria may be one of the important mechanisms of protective effect against cerebral damage caused by ischemia reperfusion.