Shlykov S G, Babich L G, Yevtushenko M E, Karakhim S O, Kosterin S O
Ukr Biochem J. 2015 Sep-Oct;87(5):54-60.
It is known that Ca(2+)-dependent regulation of this cation exchange in mitochondria is carried out with participation of calmodulin. We had shown in a previous work using two experimental models: isolated mitochondria and intact myometrium cells, that calmodulin antagonists reduce the level of mitochondrial membrane polarization. The aim of this work was to investigate the influence of calmodulin antagonists on the level of ionized Ca in mitochondria and cytoplasm of uterine smooth muscle cells using spectrofluorometry and confocal microscopy. It was shown that myometrium mitochondria, in the presence of ATP and MgCl2 in the incubation medium, accumulate Ca ions in the matrix. Incubation of mitochondria in the presence of CCCP inhibited cation accumulation, but did not cease it. Calmodulin antagonist such as trifluoperazine (100 μm) considerably increased the level of ionized Ca in the mitochondrial matrix. Preliminary incubation of mitochondria with 100 μM Ca2+, before adding trifluoperazine to the incubation medium, partly prevented influence of the latter on the cation level in the matrix. Incubation of myometrium cells (primary culture) with another calmodulin antagonist calmidazolium (10 μM was accompanied by depolarization of mitochondrial membrane and an increase in the concentration of ionized Ca in cytoplasm. Thus, using two models, namely, isolated mitochondria and intact myometrium cells, it has been shown that calmodulin antagonists cause depolarization of mitochondrial membranes and an increase of the ionized Ca concentration in both the mitochondrial matrix and the cell cytoplasm.
已知线粒体中这种阳离子交换的钙（Ca²⁺）依赖性调节是在钙调蛋白的参与下进行的。我们在先前的一项研究中使用了两种实验模型：分离的线粒体和完整的子宫肌层细胞，结果表明钙调蛋白拮抗剂会降低线粒体膜极化水平。这项工作的目的是使用荧光分光光度法和共聚焦显微镜研究钙调蛋白拮抗剂对子宫平滑肌细胞线粒体和细胞质中离子化钙水平的影响。结果表明，在孵育培养基中存在ATP和MgCl₂的情况下，子宫肌层线粒体在基质中积累钙离子。在CCCP存在的情况下孵育线粒体可抑制阳离子积累，但不会使其停止。钙调蛋白拮抗剂如三氟拉嗪（100 μM）会显著增加线粒体基质中离子化钙的水平。在向孵育培养基中添加三氟拉嗪之前，先用100 μM Ca²⁺对线粒体进行预孵育，可部分阻止后者对基质中阳离子水平的影响。用另一种钙调蛋白拮抗剂氯咪达唑（10 μM）孵育子宫肌层细胞（原代培养物）会伴随着线粒体膜去极化以及细胞质中离子化钙浓度的增加。因此，使用分离的线粒体和完整的子宫肌层细胞这两种模型已表明，钙调蛋白拮抗剂会导致线粒体膜去极化，并使线粒体基质和细胞质中的离子化钙浓度增加。
