Re L, Rossini L
Pharmacol Res Commun. 1984 Apr;16(4):381-99. doi: 10.1016/s0031-6989(84)80006-5.
The study takes the form of an analysis of the effects of cimetidine and ranitidine (2 x 10(-4) M) on 9 electrophysiological parameters, using a single frog sciatic nerve-sartorius muscle preparation. The parameters evaluated were: (i) mean end-plate potential (e.p.p.) amplitude, and mean 50%-corrected e.p.p. amplitude, (ii) mean rise time (RT), (iii) mean half-decay (HD), (iv) mean miniature end-plate potential (m.e.p.p.) amplitude, (v) mean resting membrane potential (RMP), (vi) mean m.e.p.p. frequency (f), (vii) mean quantal content (m), (viii) quantum release probability (p), and (ix) number of active sites (n) in the nerve terminal. Marquardt analysiswas used in order to determine the effects of cimetidine and raniditine on end-plate potential kinetics. At the concentration assayed only ranitidine showed a marked blocking effect at postsynaptic level as well as a less pronounced presynaptic effect. The time course of the e.p.p.'s is also more affected by raniditine, though the kinetic behaviour observed is not a unique feature of this drug alone.
该研究采用分析西咪替丁和雷尼替丁（2×10⁻⁴ M）对9个电生理参数的影响的形式，所用材料为单个青蛙坐骨神经-缝匠肌标本。所评估的参数包括：（i）平均终板电位（e.p.p.）幅度和平均50%校正后的e.p.p.幅度，（ii）平均上升时间（RT），（iii）平均半衰期（HD），（iv）平均微小终板电位（m.e.p.p.）幅度，（v）平均静息膜电位（RMP），（vi）平均m.e.p.p.频率（f），（vii）平均量子含量（m），（viii）量子释放概率（p），以及（ix）神经末梢中的活性位点数量（n）。采用Marquardt分析法来确定西咪替丁和雷尼替丁对终板电位动力学的影响。在所测定的浓度下，仅雷尼替丁在突触后水平显示出明显的阻断作用以及不太明显的突触前作用。e.p.p.的时间进程也更受雷尼替丁的影响，不过所观察到的动力学行为并非该药物独有的特征。
