汉防己碱对大鼠皮层神经元钙通道的阻滞作用

Effects of tetrandrine on calcium channels in rat cortical neurons

在急性分离的大鼠大脑皮层神经元上，用膜片钳单通道记录技术研究汉防己碱（Ｔｅｔ）对电压依赖性钙通道的影响。结果表明，Ｔｅｔ ７．５ μ ｍｏｌ／Ｌ、１５μｍｏｌ／Ｌ和３０μｍｏｌ／Ｌ可浓度依赖性抑制大鼠皮层神经元膜Ｌ－和Ｎ－型电压依赖性钙通道，使其开放时间缩短，关闭时间延长，开放概率降低，从而降低钙内流，其对Ｌ－型钙通道的作用与钙通道阻滞剂Ｖｅｍｐａｍｉｌ相似但较弱。Ｔｅｔ的多种药理作用可能与其阻滞钙通道有关。

The effects of tetrandrine (Tet ) on calcium channels in acutely isolated rat conical neurons were studied using the patch clamp single channel recording technique. The results indicated that Tet (7.5μ moll, 15 μ moll and 30 μ mol/L ) inhibited the L- and N- type calcium channels in a concentration-dependent manner. The open times of L- and N- type calcium channels decreased, the closed times increased, and open-state probability decreased. The effects of Tet on L-type calcium charmel were consistent with verapamil, a typical calcium channel antagonist, but were weaker than those of verapamil. On the other hands, the N-type calcium channel blocking effects of Tet were much stronger than those of verapamil. The multifunctions of Tet might be related to its antagonist effect on the calcium charmels.