FURTHER ANALYSIS OF INHIBITORY EFFECTS OF PROPRANOLOL AND LOCAL-ANESTHETICS ON THE CALCIUM CURRENT IN HELIX NEURONS
FURTHER ANALYSIS OF INHIBITORY EFFECTS OF PROPRANOLOL AND LOCAL-ANESTHETICS ON THE CALCIUM CURRENT IN HELIX NEURONS
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DOI：
10.1111/j.1476-5381.1982.tb09188.x
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发表时间：
1982-01-01
影响因子：
7.3
通讯作者：
OYAMA, Y
中科院分区：
文献类型：
--
作者：
AKAIKE, N;ITO, H;OYAMA, Y
1.在电压钳技术下，用吸管技术研究了普萘洛尔和局麻药对阻滞神经元钙电流（伊卡）的影响。2普萘洛尔对伊卡的抑制作用可被外Ca ~（2+）浓度的升高所克服。在存在或不存在普萘洛尔的情况下，峰伊卡与外部Ca 2+浓度的双倒数图在纵坐标处不相交。3.心得安（10 ~（-4）M）对伊卡的抑制作用为对照组的40-60%，呈时间依赖性。4.浓度为10 ~（-3）~ 10 ~（-2）M的利多卡因和普鲁卡因抑制伊卡钙电流，但不改变I-V关系的阈值。结果表明，内用木质素（10 ~（-3）~ 10 ~（-2）M）对伊卡也有抑制作用，其抑制率与外用基本相当。结果表明普萘洛尔对伊卡的抑制作用与细胞膜上的Ca ~（2+）呈非竞争性，并提示普萘洛尔可能位于细胞膜外表面和内相之间的Ca ~（2+）通道上的受体位点。
1 The effects of propranolol and local anaesthetics on Ca2+ current (Ica), individually separated from other ionic currents, in Helix neurones were studied under voltage clamp, using a suction pipette technique. 2 Increases in external Ca2+ concentrations overcame the inhibitory action of propranolol on Ica. Double reciprocal plots for peak Ica versus external Ca2+ concentrations in the presence or absence of propranolol did not intersect at the ordinate. 3 Internal application of propranolol (10-4M) inhibited Ica to about 40-60% of the control in a time-dependent manner. 4 Lignocaine and procaine at concentrations of 10-3-10-2 M inhibited Ica without shifting the threshold in the I-V relationships. Internal application of lignocaine (10-3-10-2M) also inhibited Ica: the ratio of depression of the Ica was almost equivalent to that of the agent applied externally. 5 The results provide evidence that propranolol inhibits Ica in the noncompetitive manner with Ca2+ at the cell membrane, and suggest that the agents may occupy the receptor site in the Ca2+-channel somewhere between the outer surface and inner phase of the membrane.