Galzigna L, Bianchi M, Rizzo V, Battistin T, Scarpa M, Rigo A
Department of Biochemistry, University of Padova, Italy.
Cell Biochem Funct. 1992 Jun;10(2):103-8. doi: 10.1002/cbf.290100206.
ATP added externally to rat synaptosomes activated uptake of both Ca2+ and glutamate which was partially accounted for by the uptake phenomena of synaptic vesicles and mitochondria, as shown by using specific inhibitors of the latter. Increasing concentrations of glutamate stimulated Ca2+ entry linearly, as shown by using 45Ca or a Ca-specific electrode. The processes of glutamate and Ca2+ uptake shared some common features and their ATP-dependence may be correlated with an ouabain-insensitive synaptosomal ectonucleotidase activity measured by a 31P-NMR or a luminometric technique. The ATP hydrolysis catalysed by the synaptosomes was activated by both Ca2+ and glutamate. The present synaptosomal activities may represent a model for studying the modulatory effects of ATP on the glutamatergic neurotransmission.
向大鼠突触体外部添加的ATP可激活Ca2+和谷氨酸的摄取，其中部分摄取现象可由突触小泡和线粒体的摄取来解释，这通过使用后者的特异性抑制剂得以证明。如使用45Ca或Ca特异性电极所示，谷氨酸浓度的增加会线性刺激Ca2+内流。谷氨酸和Ca2+摄取过程具有一些共同特征，它们对ATP的依赖性可能与通过31P-NMR或发光技术测量的哇巴因不敏感的突触体胞外核苷酸酶活性相关。突触体催化的ATP水解可被Ca2+和谷氨酸激活。目前的突触体活性可能代表了一个研究ATP对谷氨酸能神经传递调节作用的模型。
