Martínez-Serrano A, Satrústegui J
Departamento de Biología Molecular, Universidad Autónoma de Madrid, Spain.
Biochem Biophys Res Commun. 1989 Jun 30;161(3):965-71. doi: 10.1016/0006-291x(89)91337-5.
Ca2+-sensitive minielectrodes and the fluorescent cytosolic calcium probes, quin2 and fura2, were used to study some aspects of calcium homeostasis in intact and permeabilized synaptosomes from whole rat brain. Experiments in permeabilized synaptosomes revealed the existence of a vesicular, non-mitochondrial, ATP-dependent calcium uptake system with a vanadate sensitivity similar to that of brain microsomes, or endoplasmic reticulum-type calcium sequestering organelles. By using the fluorescent probes it was possible to show that caffeine mobilizes calcium from these internal stores in intact synaptosomes. Our results indicate a role of the caffeine sensitive calcium stores in the buffering of calcium loads elicited by plasma membrane depolarization.
利用钙敏感微电极以及荧光细胞质钙探针喹2和fura2，研究了来自全大鼠脑的完整和通透突触体中钙稳态的某些方面。对通透突触体的实验揭示了存在一种囊泡性、非线粒体、依赖ATP的钙摄取系统，其对钒酸盐的敏感性与脑微粒体或内质网型钙螯合细胞器相似。通过使用荧光探针，有可能表明咖啡因可从完整突触体中的这些内部储存库中动员钙。我们的结果表明，对咖啡因敏感的钙储存库在缓冲质膜去极化引发的钙负荷方面发挥作用。
