缺血等因素对大鼠心肌线粒体Ca^(2+)转运的影响

Effects of Ischemia and Other Factors on Rat Heart Mitochondrial Ca^(2+) Transport

本研究检测了体外缺血等因素对心肌线粒体Ca^(2+)转运的影响。结果表明,缺血明显抑制线粒体Ca^(2+)-ATP酶活性及^(45)Ca摄取率。缺血10分钟时,线粒体Ca^(2+)-ATP酶活性开始下降,40分钟时显著降低,^(45)Ca摄取率的变化也呈类似趋势。去甲肾上腺素及cAMP对线粒体Ca^(2+)-ATP酶活性,^(45)Ca摄取率无任何影响。无机磷对线粒体Ca^(2+)-ATP酶有轻微的抑制作用,二磷酸腺苷对谚酶活性有明显抑制作用,其IC_(50)值为2.5mmol/L。

In present study, we examined in vitro the effects of ischemia , noradre-nalin (NE) , cAMP, ADP on heart mitochondrial Ca2 + transport. The result showed that myocardial ischemia inhibited mitochondrial Ca2+-ATPase and rate of 45Ca uptake obviously.Decrease of mitochondrial Ca2+-ATPase activity appeared at 10 min after resultant ischmia and even after 40 min of ischemia the enzyme activity fell down to the level which is less than half of the original activity. The variation of the 45Ca uptake was similar to the Ca2+-ATPase activity.NE and cAMP did not display any effect on mitochondrial Ca2+-ATPase and 45Ca uptake.Pi inhibited the activity of mitocondrial Ca2+ -ATPase slightly, however, ADP inhibited the enzyme activity markedly with IC50 of 2.5 mmol/L.