Neuroligand‐Evoked Calcium‐Dependent Release of Excitatory Amino Acids from Cultured Astrocytes
Neuroligand‐Evoked Calcium‐Dependent Release of Excitatory Amino Acids from Cultured Astrocytes
复制标题
神经配体诱发培养星形胶质细胞钙依赖性兴奋性氨基酸的释放
作者：
S. Jeftinija;K. Jeftinija;G. Stefanović;Fang Liu
翻译后摘要：兴奋性氨基酸（EAAs）的释放从神经元的新皮层星形胶质细胞的无培养物进行了监测，使用HPLC。神经配体缓激肽导致从大鼠大脑皮层获得的1型星形胶质细胞培养物中EAA谷氨酸和天冬氨酸释放的剂量依赖性受体介导的增加。从细胞外液中去除钙阻止了缓激肽诱导的星形胶质细胞释放EAA。钙离子载体离子霉素的添加引起EAA的钙依赖性释放。谷氨酸转运蛋白对氯汞苯磺酸、l-反式-吡咯烷-2，4-二羧酸和二氢红藻氨酸的抑制剂未能损害缓激肽刺激星形胶质细胞释放谷氨酸的能力。α-蛇麻毒素是黑寡妇蜘蛛毒液的活性化合物，在含钙盐水中引起谷氨酸释放的显著增加。在去钙生理盐水中，α-latrotoxin引起谷氨酸浓度的初始增加，随后谷氨酸浓度下降，表明胞吐刺激与低钙诱导的内吞抑制相结合。总之，这些数据表明，星形胶质细胞可能通过类似于神经元分泌过程的机制释放神经递质。鉴于谷氨酸在诱导长时程增强、学习、记忆和兴奋性毒性中的重要作用，确定控制星形胶质细胞摄取和释放谷氨酸的外部信号将是重要的。
Abstract: The release of excitatory amino acids (EAAs) from neuron‐free cultures of neocortical astrocytes was monitored using HPLC. The neuroligand bradykinin caused a dose‐dependent receptor‐mediated increase in release of the EAAs glutamate and aspartate from type 1 astrocyte cell cultures obtained from rat cerebral cortex. Removal of calcium from the extracellular fluid prevented the bradykinin‐induced release of EAAs from astrocytes. The addition of the calcium ionophore ionomycin caused a calcium‐dependent release of EAAs. Inhibitors of the glutamate transporters p‐chloromercuriphenylsulfonic acid, l‐trans‐pyrrolidine‐2,4‐dicarboxylate, and dihydrokainate failed to impair the ability of bradykinin to stimulate glutamate release from astrocytes. α‐Latrotoxin, an active compound of black widow spider venom, caused a significant increase of the release of glutamate in calcium‐containing saline. In calcium‐depleted saline, α‐latrotoxin produced an initial increase in the concentration of glutamate followed by a decline in the concentration of glutamate indicating stimulation of exocytosis coupled with low calcium‐induced inhibition of endocytosis. Taken together, these data suggest that astrocytes may release neurotransmitter through a mechanism that is similar to the neuronal secretory process. Given the important role of glutamate in the induction of long‐term potentiation, learning, memory, and excitotoxicity, it will be important to determine external signals that control both the uptake and release of glutamate by astrocytes.
DOI：
10.1073/pnas.87.9.3454
发表时间：
1990-05-01
影响因子：
11.1
作者：
GLAUM, SR;HOLZWARTH, JA;MILLER, RJ
通讯作者：
MILLER, RJ
包埋 Fura 2 的脂质体中的离子霉素和磷脂酸介导的跨膜钙运动。
影响因子：
2.9
作者：
Blau,L;Weissmann,G
通讯作者：
Weissmann,G
影响因子：
56.9
作者：
CORNELLBELL, AH;FINKBEINER, SM;SMITH, SJ
通讯作者：
SMITH, SJ