乌头碱修饰的钠通道对有髓神经中单价阳离子的通透性。 - Suppr | 超能文献

乌头碱修饰的钠通道对有髓神经中单价阳离子的通透性。

The permeability of aconitine-modified sodium channels to univalent cations in myelinated nerve.

Mozhayeva G N, Naumov A P, Negulyaev Y A, Nosyreva E D

Biochim Biophys Acta. 1977 May 2;466(3):461-73. doi: 10.1016/0005-2736(77)90339-x.

Abstract

Ionic currents through the sodium system of nodes of Ranvier treated with aconitine were measured under voltage clamp conditions in a Ringer solution containing Na+ or an equimolar amount of various test cations. 2. Average shifts in reversal potentials in nodes of Ranvier treated with aconitine with NH4+, Li+, K+, Rb+, Cs+ in place of Na+ in the Ringer solution are 7.6, --6.8, --25.0, --41.0 and --51.5 mV at 13--14degrees C. At 20--22degrees C the sequence of shifts is 7.5, --5.5, --13.5, --29.0 and --41.0 mV. For Tl+ the the average reversal potential shift is +3 mV at 20--22degrees C. 3. The slope of the instantaneous current-voltage relation at the reversal potential in nodes treated with aconitine changed with the various cations tested. The ratios are NH4+/Na+/K+/Rb+/Cs+/Li+ = 1.14 : 1.0 : 0.80 :0.67 :0.53 : 0.53. 4. Using a three energy barrier model some of the parameters for the aconitine-modified Na+ channels were estimated (Chizmadgev, Yu. A., Khodorov, B.I. and Aityan, S.Kh. (1974) Bioelectrochem. Bioenerg. 1, 301--312).

摘要

在含有Na⁺或等摩尔量各种测试阳离子的林格氏溶液中，于电压钳制条件下测量了用乌头碱处理的郎飞结钠系统中的离子电流。2. 在13 - 14摄氏度时，用乌头碱处理的郎飞结中，当林格氏溶液中的Na⁺被NH₄⁺、Li⁺、K⁺、Rb⁺、Cs⁺取代时，反转电位的平均偏移分别为7.6、 - 6.8、 - 25.0、 - 41.0和 - 51.5 mV。在20 - 22摄氏度时，偏移顺序为7.5、 - 5.5、 - 13.5、 - 29.0和 - 41.0 mV。对于Tl⁺，在20 - 22摄氏度时反转电位的平均偏移为 + 3 mV。3. 用乌头碱处理的节点在反转电位处的瞬时电流 - 电压关系的斜率随所测试的各种阳离子而变化。其比例为NH₄⁺/Na⁺/K⁺/Rb⁺/Cs⁺/Li⁺ = 1.14 : 1.0 : 0.80 : 0.67 : 0.53 : 0.53。4. 使用三能垒模型估算了乌头碱修饰的Na⁺通道的一些参数（奇兹马杰夫，尤·阿，霍多罗夫，B.I.和艾季扬，S.Kh.（1974年）《生物电化学与生物能量学》1，301 - 312）。