Mode of Action of Anesthetics on Neuro-muscular Junction

麻醉药的术前和术后效应本文研究了筒箭毒碱（tubocurarine）、肌松药和其它相关药物在人四串刺激中的作用。筒箭毒碱和相关药物明显通过阻断连接前乙酰胆碱受体而使神经刺激诱发的反应减弱或消退（Bowman等人，《麻醉研讨会》，3：275- 283，1984），（1）阻断连接后受体，一种不依赖于刺激频率的效应;（2）阻断连接前受体，导致乙酰胆碱释放的初始进行性减少。本文研究了氟烷、甲氧氟醚、乙醚、硫代戊醛、丙苯胺、氯胺酮和乙酰氨基酚等麻醉药对手术病人四联反应的影响<T_4>。所有这些药物单独使用时的比例没有变化<T_4>。二乙醚甲氧氟醚<T_4>在部分管箭毒阻滞时降低比率，在琥珀胆碱神经肌肉阻滞时，氟烷&gt;二乙醚&gt;甲氧氟醚降低<T_4>比率，而其他药物对比率无影响。因此，这3种吸入麻醉药阻断了连接前和连接后的乙酰胆碱受体。在麻醉手术患者中进行的非去孔肌松药（阿库溴铵、筒克碱、维库溴铵和泮库溴铵）作用的研究。所有四种非去孔肌松药产生了四列褪色，但在每种情况下，伴随褪色的单抽搐抑制的程度不同。阿库溴铵的四联衰减程度更明显，依次为筒箭毒碱、维库溴铵和泮库溴铵。因此，阿库溴铵似乎对胆碱受体的连接前（参与褪色的位点）位点具有相对较大的亲和力。

Pre- and postjumctional effects of anesthetics ( inhalationl&intravenous ),muscle relaxants and other related drugs during train-of-four stimulation were investigated in man. Since tubocurarine and related drungs produce rundown or fade of responses evoked by nerve stimulation apparently by blocking prejunctional acetylcholine receptors ( Bowman et al. Semin in Anesthesia,3:275-283,1984 ), (1)block of postjunctional receptors, an effect that is independent of stimulation frequency (2)block of prejunctional receptors resulting in an initial progressive diminution of acetylcholine release. The effects of anesthetics ( halothane, methoxyflurane, diethylether, thiamylal, propanidid, ketamine and althesin ) on train-of-four ratio ( <T_4> ratio ) were studred in surgical patients. All these agents alone did not change in <T_4> ratio. Diethylether methoxyflurane decreased in <T_4> ratio during partial tubocurarine blockade.During neuromuscular blockade produced by succinylcholine, halothane>diethylether> methoxyflurane decreased <T_4> ratio, while other agents did not alter the ratio. Therefore, these 3 inhalational anesthetics block pre- and postjunctional acetylcholine choline receptors. Studies on anesthetized surgical patients in which the effects of non-deporalizing muscle relaxants ( alcuronium, tubocrarine, vecuronium and pancuronium ) were performed. All four non-deporalizing muscle relaxants produced train-of-four fade, but the degree of single twitch depression that accompanied the fade differed in each case. The degree of train-of-four fade was much more pronouned with alcuronium and following the order of tubocurarine, vecuronium and pancuronium. Therefore, alcuronium appears to have a relatively greater affinity to the prejunctional ( site involved in fade ) sites of the cholinoceptors.