N-methyl-D-aspartate increases cytoplasmic free calcium in mouse hippocampus.
N-methyl-D-aspartate increases cytoplasmic free calcium in mouse hippocampus.
复制标题
N-甲基-D-天冬氨酸增加小鼠海马中的细胞质游离钙。
DOI：
10.1016/0028-3908(91)90071-i
复制
发表时间：
1991
影响因子：
4.7
通讯作者：
Daniell,LC
中科院分区：
文献类型：
--
作者：
Daniell,LC
本文观察了N-甲基-D-天冬氨酸（NMDA）和L-谷氨酸对离体小鼠脑微囊和突触体细胞内游离钙（CaI）浓度和钙摄取的影响。L-谷氨酸和NMDA使海马微囊CaI增加，而对离体小鼠皮层、小脑微囊和突触体细胞内CaI无影响。N-甲基-D-天冬氨酸也使离体小鼠脑微囊和突触体细胞内CaI增加，用45 Ca测量海马微囊。NMDA刺激的CaI增加和微囊钙摄取的EC_（50）值约为30 μM。在100 μM NMDA下观察到最大反应。由NMDA刺激的Cais的增加依赖于细胞外钙，表明NMDA通过增加NMDA受体操作的阳离子通道的电导来增加Caiin微囊，而不是通过从细胞内储存释放钙来增加Caiin微囊。NMDA拮抗剂5-甲基-10，11-二氢-5H-二苯并[a，d]环庚烯-5，10-亚胺（MK-801）、2-氨基-5-膦酰基戊酸（AP-5）、镁和锌可阻断对NMDA的反应。这证明了NMDA介导的对来自脑的无细胞制剂中离子通量的影响。该制剂可用于研究药物或毒素对脑内NMDA受体的影响。
The effect ofN-methyl-d-aspartate (NMDA) andl-glutamate on the concentration of intracellular free calcium (Cai) and on uptake of the calcium was determined in microsacs and synaptosomes isolated from mouse brain.l-Glutamate and NMDA increased Caiin hippocampal microsacs but had little or no effect on Caiin microsacs, isolated from cortex or cerebellum or in synaptosomes.N-Methyl-d-aspartate also increased uptake of calcium, measured using45Ca into hippocampal microsacs. The EC50values for NMDA-stimulated increases in Caiand uptake of calcium in microsacs were about 30 μM. Maximum responses were observed with 100 μM NMDA. Increases in Caistimulated by NMDA were dependent on extracellular calcium, indicating that NMDA increased Caiin microsacs by increasing conductance through an NMDA receptor-operated cation channel, rather than by releasing calcium from intracellular stores. The NMDA antagonists, 5-methyl-10, l l-dihydro-5H-dibenzo [a,d]cyclohepten-5,10-imine (MK-801), 2-amino-5-phosphonopentanoic acid (AP-5), magnesium and zinc blocked responses to NMDA. This demonstrates NMDA-mediated effects on ion flux in a cell-free preparation from brain. This preparation may be useful for study of thein vitroeffects of drugs or toxins on NMDA receptors in brain.