KAPPA-OPIOID RECEPTORS ON ASTROCYTES STIMULATE L-TYPE CA2+ CHANNELS

被引：62

作者：

ERIKSSON, PS ^{[1
]}

NILSSON, M ^{[1
]}

WAGBERG, M ^{[1
]}

HANSSON, E ^{[1
]}

RONNBACK, L ^{[1
]}

机构：

[1] UNIV GOTEBORG,DEPT NEUROL,S-41390 GOTHENBURG,SWEDEN

来源：

NEUROSCIENCE | 1993年 / 54卷 / 02期

关键词：

D O I：

10.1016/0306-4522(93)90261-D

中图分类号：

Q189 [神经科学];

学科分类号：

071006 ;

摘要：

Cultured astrocytes from the cerebral cortex of the rat respond to opioid kappa-receptor stimulation with a substantial elevation of the cytoplasmic free calcium, visualized through the use of the fluorescent calcium indicator Fura-2. The stimulation of kappa-receptors with U-50488H increases the level of calcium through a dose-related stimulatory effect on the transmembrane calcium influx. The kappa-receptor stimulation was completely blocked by the selective kappa-receptor blocker nor-binaltorphimine. Furthermore, the transmembrane calcium influx was completely blocked by nifedipine, indicating the involvement of L-type channels. The presence Of L-type channels was verified by stimulation of L-type channels with Bay K8644. The effects of Bay K8644 were completely blocked by nifedipine. L-type channel-coupled kappa-receptors on astrocytes might represent a novel mechanism contributing to the depressant action of opioids on synaptic transmission via decreasing the availability of extracellular calcium necessary for presynaptic transmitter release.

引用

页码：401 / 407

页数：7

共 37 条

[1] PRESYNAPTIC ALPHA-2-ADRENOCEPTOR AND KAPPA-OPIATE RECEPTOR OCCUPANCY PROMOTES CLOSURE OF NEURONAL (N-TYPE) CALCIUM CHANNELS [J].