摘要
用显微荧光测量技术研究了纯化培养的大鼠神经胶质细胞的内质网钙库的组成、特征。用IP3 敏感的和非IP3 敏感的钙库的激活剂乙酰甲胆碱 (Acetyl β MethylcholineChloride ,MCh)和咖啡因 (Caffeine ,CAF)及线粒体解偶剂FCCP组成不同的刺激条件作用于细胞 ,观察胞内钙信号的变化。结果表明MCh和CAF均可使[Ca2 +]i出现与刺激浓度依赖性的钙升高。快速重复的刺激可导致钙库的耗竭 ,而足够长的间隔时间可使钙库的Ca2 +储存得到不同程度的恢复 ;用Thapsigargin耗竭内质网钙库后 ,MCh和CAF不能引起 [Ca2 +]i升高 ;线粒体的解偶剂FCCP可诱发中度的 [Ca2 +]i升高 ,并与MCh和CAF敏感的钙库相对独立。研究显示星形胶质细胞内的钙库包括 :MCh和CAF敏感的两种内质网钙库 ,它们或相对独立或密切相关 ;线粒体钙库参与胞质内Ca2 +缓冲系统。
Microfluorescent technique was used to research the components and property of endoplasmic reticulum calcium stores in rat astrocytes. Acetyl β methylcholine chloride (MCh), caffeine (CAF), thapsigargin and carbonyl cyanide p trifluomethoxphenylhydrazone(FCCP) were used to stimulate astrocytes by different combination, their effects on the ratio of cytosolic calcium were observed. Both MCh and CAF could induce \[Ca 2+ \] i increase in a concentration dependent manner.Rapid and repetitive stimulation could exhaust the calcium stores, but they could recover at different extent when the intervals of stimulation are increased.Exhausting the endoplasmic reticulum calcium store with thapsigargin could inhibit the response induced by MCh and CAF.FCCP could induce mild increase of \[Ca 2+ \] i which was relative independent of MCh and CAF sensitive calcium stores. It suggests that there are two types of calcium stores in the astrocytic endoplasmic reticulum-IP 3 sensitive and non-IP 3 sensitive calcium stores, having intimate or relative in dependent relationship and mitochondrial store takes part in calcium ion buffer system as well.
基金
国家自然科学基金资助项目 (3 0 0 40 0 3 7)
