羟自由基对心肌线粒体膜的影响及硒的效应

THE INFLUENCE OF HYDROXYL RADICAL (OH.) ON CARDIAC MITOCHONDRIA MEMBRANE AND TEH ANTAGONSTIC EFFCT OF Se-COMPOUNDS

由Ｈ２Ｏ２和ＦｅＳＯ４体系产生的羟自由基（ＯＨ·）作用于大鼠心肌线粒体后，其膜脂双层内产生了脂类自由基。在观测时间内，其脂类自由基与自旋捕捉剂形成的自旋加合物的电子自旋共振（ＥＳＲ）信号强度随着孵育时间的延长而加强。一定浓度的硒代蛋氨酸（Ｓｅ—Ｍｅｔ）或Ｎａ２ＳｅＯ３可明显清除ＯＨ·并抑制脂类自由基的产生。在ＯＨ·的影响下，荧光探针ＤＰＨ在心肌线体膜脂中的荧光寿命和膜脂流动性的测试结果发生了明显变化。与此同时，心肌线粒体膜的能量转换过程（氧化磷酸化效率和呼吸控制率）也发生了显著的改变。１．０μｍｏｌ／Ｌ的Ｓｅ—Ｍｅｔ或２．３μｍｏｌ／Ｌ的Ｎａ２ＳｅＯ３可明显拮抗ＯＨ·的上述影响。前者的作用更为显著。

Lipid free radicals could be detected following betment of rat heart mitochondria by hydroxyl radical (OH. ),which were produced in a system containing H2O, and FeSO4. Using spin trap 4-POBN [α- (4-pyridyl- 1 -oxide) -N-t-butylnitronel, an ESR signal of 4-POBN spin adduct was recorded, and its intensity was increased with the elongation of incubation time. OH. could induce change in inembrane lipid fluldity and the life time of fluoascence of DPH monitoral by nanosecond spectrofluorometer. A concomitant change of ADP[O and RCR value was also detected. Obtained adults showed that the hydroxyl - radical - induce changes might be inhibital in the presence of Se - Met or Na2SeO3 at an appropriate concentlation, and the former was more effusive.