Meldolesi J, Villa A, Podini P, Clementi E, Zacchetti D, D'Andrea P, Lorenzon P, Grohovaz F
Department of Pharmacology, CNR Cytopharmacology, Milan, Italy.
J Physiol Paris. 1992;86(1-3):23-30. doi: 10.1016/s0928-4257(05)80004-x.
Various aspects of the rapidly exchanging intracellular Ca2+ stores of neurons and nerve cells are reviewed: their multiplicity, with separate sensitivity to either the second messenger, inositol 1,4,5-trisphosphate, or ryanodine-caffeine (the latter stores are probably activated via Ca(2+)-induced Ca2+ release); their control of the plasma membrane Ca2+ permeability, via the activation of a peculiar type of cation channels; their ability to sustain localized heterogeneities of the [Ca2+]i that could be of physiological key-importance. Finally, the molecular composition of these stores is discussed. They are shown (by high resolution immunocytochemistry and subcellular fractionation) to express: i) a Ca2+ ATPase responsible for the accumulation of the cation; ii) Ca2+ binding protein(s) of low affinity and high capacity to keep Ca2+ stored; and iii) a Ca2+ channel, activated by either one of the mechanisms mentioned above, to release Ca2+ to the cytosol. Results obtained in Purkinje neurons document the heterogeneity of the stores and the strategical distribution of the corresponding organelles (calciosomes; specialized portions of the ER) within the cell body, dendrites and dendritic spines.
它们的多样性，对第二信使肌醇1,4,5 - 三磷酸或ryanodine - 咖啡因具有不同的敏感性（后者的储存可能通过钙诱导的钙释放激活）；它们通过激活一种特殊类型的阳离子通道来控制质膜对钙离子的通透性；它们维持细胞内钙离子浓度局部异质性的能力，这可能具有重要的生理意义。最后，讨论了这些储存的分子组成。通过高分辨率免疫细胞化学和亚细胞分级分离表明，它们表达：i）负责阳离子积累的钙离子ATP酶；ii）具有低亲和力和高容量以储存钙离子的钙离子结合蛋白；iii）由上述任何一种机制激活的钙离子通道，将钙离子释放到细胞质中。在浦肯野神经元中获得的结果证明了储存的异质性以及相应细胞器（钙体；内质网的特化部分）在细胞体、树突和树突棘内的战略分布。
