小檗碱对培养大鼠神经细胞内游离Ca^(2+)的影响

EFFECT OF BERBERINE ON INTRACELLULAR FREE CA 2+ CONCENTRATION IN CULTURED BRAIN CELLS

以Ｆｕｒａ２／ＡＭ为细胞内钙离子的荧光指示剂，用ＡＲＣＭＭＩＣ阳离子测定系统，直接测定了体外培养的新生大鼠神经细胞内游离钙（［Ｃａ２＋］ｉ）值，并观察了小檗碱（Ｂｅｒ）的影响。结果表明，Ｂｅｒ对神经细胞静息［Ｃａ２＋］ｉ无明显影响，Ｂｅｒ１～１００μｍｏｌ·Ｌ－１能剂量依赖地抑制去甲肾上腺素和Ｈ２Ｏ２引起的［Ｃａ２＋］ｉ升高，其ＩＣ５０分别为３９．９和１７．９μｍｏｌ·Ｌ－１。高剂量Ｂｅｒ（１０～１００μｍｏｌ·Ｌ－１）能抑制高Ｋ＋引起的［Ｃａ２＋］ｉ升高。姐果提示，Ｂｅｒ对去甲肾上腺素，高Ｋ＋及Ｈ２Ｏ２引起的［Ｃａ２＋］ｉ升高的抑制作用可能是其抗脑缺血作用机制之一。

Intracellular free calcium concentration ([Ca 2+ ]i) was measured with Ca 2+ sensitive fluorescent indicator, Fura 2/AM, in cultured brain cells using AR CM MIC cation measurement system, and the effects of berberine(Ber) on the changes in [Ca 2+ ]i induced by CaCl 2, norepinephrine, KCl and H 2O 2 were studied. The results indicate that the resting [Ca 2+ ]i was 35±8 nmol·L -1 in Ca 2+ free Hank′s solution. Ber showed no effect on the resting [Ca 2+ ]i when the extracellular Ca 2+ were 0.01～10 mmol·L -1 . Ber 1～100 μmol·L -1 dose dependently inhibited norepinephrine and H 2O 2 induced [Ca 2+ ]i elevation. Ber at high concentration(10～100 μmol·L -1 ) inhibited K + induced [Ca 2+ ]i elevation. This suggests that the inhibitory effects of Ber on norepinephrine, K + , and H 2O 2 induced [Ca 2+ ]i elevation may be one of the mechanisms against cerebral ischemia.