谷氨酸触发大鼠大脑皮质神经元Ca~(2+)内流与PTK的关系

目的　研究谷氨酸 (glutamate,Glu)触发大鼠大脑皮质神经元Ca2 + 内流特性 ,蛋白酪氨酸激酶 (PTK)抑制剂genistein及蛋白酪氨酸磷酸酶 (PTP)抑制剂vanadate对其影响 ,揭示PTK与Glu触发大鼠大脑皮质神经元Ca2 + 内流的内在联系。方法　采用Fura 2 /AM荧光测定胞浆Ca2 + 变化技术 ,在原代培养的大鼠大脑皮质神经元上观察药物对Glu触发Ca2 + 内流的影响。结果　Glu触发的Ca2 + 内流不受电压依赖性钙通道 (VDCC)阻断剂尼莫地平影响 ,亦不受非VDCC阻断剂SK&F96 36 5影响 ,但可被PTK抑制剂genis tein抑制 ,被PTP抑制剂vanadate增强。genistein(1～ 30μmol·L-1)呈浓度依赖性抑制Glu触发的Ca2 + 内流。vana date则浓度依赖性增强Glu触发的Ca2 + 内流。结论　对尼莫地平敏感的VDCC及对SK&F96 36 5敏感的非VDCC没有参与Glu触发的Ca2 + 内流。PTK激活参与了Glu触发的Ca2 + 内流

The roles of protein tyrosine kinase at glutamate-induced Ca2+ entry in primary cultured corticocerebral neurons

AIM To investigate effects of genistein, an inhibitor of protein tyrosine kinase and vanadate, the inhibitor of protein tyrosine phophorylation, on glutamate induced Ca 2+ entry in rat primary cultured corticocerebral neurons. METHODS The effects of drug on cytoplasmic Ca 2+ level(Ca 2+ ] i) were invesgated with Fura 2/AM fluorescence technique. RESULTS The increase in Ca 2+ ] i induced by glutamate was significantly reduced by genistein (from 1 to 30 μmol·L -1 ) and NMDA receptor antagonist MK 801 (1 μmol·L -1 ), not by nimodipine(1 μmol·L -1 ) and SK&F96365. Vanadate (from 1 to 30 μmol·L -1 ) significantly enhanced glutamine induced Ca 2+ ] i response. CONCLUSION Nimdipine sensitive Ca 2+ channel and SK&F96365 sensitive Ca 2+ channels are not related to glutamate induced Ca 2+ entry. It is related to the activation of protein tyrosine kinase in rat primary cultured corticocerebral neurons.