海人藻酸对脑细胞胞浆游离钙的影响

The effect of Kanic acid on Ca 2+ in brain cells

目的探讨脑内细胞钙离子与发生阿尔茨海默病（ＡＤ）之间的关系。方法用兴奋性神经毒海人藻酸（ＫＡ）破坏Ｍｅｙｎｅｒｔ基底核（ＮＢＭ），复制出与人类ＡＤ相似的大鼠脑神经病理改变模型。采用Ｆｕｒａ－２／ＡＭ测定乳鼠脑细胞游离钙的方法观察ＫＡ的影响。同时应用尼卡地平、氯化钾作为电压依赖性钙通道阻滞剂与激动剂，确定ＫＡ是通过何种钙通道促使钙内流的。结果用不同浓度ＫＡ均可以使乳鼠脑细胞胞浆游离钙浓度明显升高（Ｐ＜０．０５），并证实ＫＡ是通过电压依赖性钙通道使钙离子流入脑细胞的。用同属兴奋性神经毒的谷氨酸可通过受体依赖性钙通道使脑细胞胞浆游离钙增多（Ｐ＜０．０５）。结论ＫＡ可使鼠脑细胞内钙超载，后者与ＡＤ的发生有关。

Objective The purpose of this study was to explore the relation between Ca 2+ in brain cells and Alzheimer′s disease(AD). Methods The experimental rats were injected an excitotoxin, kanic acid (KA) to destroy the nucleus basal of Meynert (NBM) to made a brain pathological model of Alzheimer ,s disease. The effect of KA on brain cells Ca 2+ in sucking rats were tested with Fura 2/AM. Nikadipine, KCl, as the voltage dependent calcium channel ,s activator and blockade were used to determine that KA through what channel made Ca 2+ to flow into brain cells. Results KA with different concentration could increase the [Ca 2+ ]i in brain cells of sucking rats ( P <0.05). KA caused Ca 2+ to flow into brain cells through the voltage dependent calcium channel. In addition, glutamate, as an excitotoxin, though receptor dependent calcium channel increased [Ca 2+ ]i in brain cells ( P <0.05). Conclusion It is suggested that KA could cause the overload of Ca 2+ in brain cells, which may be linked to the development of AD.