Satrustegi D, Bogonez E, Vitorika Zh, Blanko P, Martinez-Serrano A
Center of Molecular Biology, University of Madrid, Spain.
Fiziol Zh (1978). 1990 Sep-Oct;36(5):42-50.
Studies were undertaken on the age-associated peculiarities of the Ca2+ transport systems of the rat brain synaptosomes. It has been found that 45Ca2+ uptake reduced with ageing. The above reduction was not linked with the changes in the permeability of potential-dependent synaptosomal membrane Ca2+ depending upon the membrane potential. The distribution of calcium across the mitochondrial membrane changed with ageing, shifting towards higher extramitochondrial calcium levels in old rats, both in isolated and in synaptosomal mitochondria. While studying calcium efflux from mitochondria, it was found that, at equivalent calcium loads, the calcium efflux rates were slower in old rats as compared to adult animals. As observed, both resting [Ca2+]i and that obtained after K-depolarization drastically increased in old animals. The possible pathogenic mechanisms in neuronal injury, conditioned by this increase, are discussed.
对大鼠脑突触体Ca2+转运系统的年龄相关特性进行了研究。已发现45Ca2+摄取量随衰老而减少。上述减少与依赖膜电位的突触体膜Ca2+通透性变化无关。随着衰老，钙在线粒体膜上的分布发生变化，在老年大鼠的分离线粒体和突触体线粒体中，都向线粒体外钙水平较高的方向转变。在研究线粒体钙外流时发现，在相同钙负荷下，老年大鼠的钙外流速率比成年动物慢。观察到，老年动物的静息[Ca2+]i和钾去极化后获得的[Ca2+]i都大幅增加。讨论了由此增加导致神经元损伤的可能致病机制。
