氯化筒箭毒碱抑制蟾蜍椎旁神经节胆碱能传递的时反应量－效关系

应用离体蟾蜍椎旁神经节（ＰＶＧ）细胞内记录技术，测得灌流氯化筒箭毒碱（ｄ－ＴＣ）１５ｍｉｎ抑制ＰＶＧ快突触反应（ｆ－ＥＰＳＰ）的ＥＣＳ５０±Ｌ９５（斜率）为２１±８（３．１９８）μｍｏｌ·Ｌ－１，并发现作用的潜伏期和时程呈浓度依赖性关系（Ｐ＜０．０５）．其双曲线型四参数模型的拟合方程分别为：＝１８９．００５４／（ｌｎ＋Ｏ．２９７２）１．９５３７－２．４８０６和＝１５２．８３８８／（６．３９４５－ｌｎ）２．２１９９－０．３２０９。结果表明ｄ－ＴＣ对离体蟾蜍ＰＶＧ胆碱能传递的抑制作用存在双曲线型时反应量─效关系。

Timed dose-response relationship of inhibitory action of d-tubocurarine chloride on cholinergic transmission in toad paravertebral ganglia

The median effective concentration (EC50) and timed dose-response relationship(TDRR) of inhibitory action of d-tubocurarine chloride(d-TC) by 15 minsuperfusion on cholinersic transmission(fEPSPs) in the toad paravertebral ganglia (PVG) were studied by means of the intracellular recording techniques. . The EC50±L95 (slope) of d-TC calculated by Bliss method was 21±8(3.198)μmol·L-1.in which L95 is the average confidence limit of 95% . It was found that the latency and duration of d-TC action were concentrationdependent( F' test. P< 0. 05) .The TDRRdata were nonlinear least-square fit to the hyperbolic four-parameter model Ⅱthat is,=189.0054/(ln 2972) 1.9537-2.4806 for latency data and =152.8388/(6.3945-lnX)2.2199-0.3909 for duration respectively. in which Xis concentration. It is proved that the hyperbolic type of TDRR is present in the inhibitory action of d-TC on cholinergic transmission of toad PVGneurons in vitro.