Re L, Di Sarra B
Institute of Experimental and Clinical Medicine, University of Ancona, Italy.
Pharmacology. 1989;39(3):200-4. doi: 10.1159/000138598.
The effects of some histamine H2-receptor antagonists on the cholinergic system have been evaluated at the mouse end-plate. Previous data revealed interactions at both pre- and postsynaptic sites for cimetidine and ranitidine. The present work shows the effects of the same two drugs, and of famotidine, on some parameters related to the neuromuscular transmission. Ranitidine potentiates the amplitude of the spontaneously occurring miniature end-plate potentials. Famotidine reduces the same parameter. A common effect achieved with higher concentrations of the three drugs is the reduction of the quantal content. The kinetic parameters of the quantal conductance change is lengthened, in a different manner, by all the assayed drugs too. These results, besides strengthening the hypothesis of an inhibitory action of ranitidine on acetylcholinesterase, indicate a collateral inhibitory effect at presynaptic levels of cimetidine, ranitidine and famotidine.
一些组胺H2受体拮抗剂对胆碱能系统的作用已在小鼠终板处进行了评估。先前的数据显示，西咪替丁和雷尼替丁在突触前和突触后位点均存在相互作用。目前的研究表明了这两种药物以及法莫替丁对一些与神经肌肉传递相关参数的影响。雷尼替丁可增强自发出现的微小终板电位的幅度。法莫替丁则降低相同的参数。三种药物在较高浓度时产生的一个共同作用是降低量子含量。所有受试药物也以不同方式延长了量子电导变化的动力学参数。这些结果除了强化雷尼替丁对乙酰胆碱酯酶具有抑制作用的假说外，还表明西咪替丁、雷尼替丁和法莫替丁在突触前水平具有附带的抑制作用。
