Son S L, Waud B E
Anesthesiology. 1977 Jul;47(1):34-6. doi: 10.1097/00000542-197707000-00008.
Drug receptor dissociation constants (KB) were determined for four neuromuscular relaxants at the cardiac pacemaker as well as at the motor endplate. The ratios KB(atrium)/KB(lumbrical) were found to be high for d-tubocurarine and dimethyltubocurarine, 264 and 136, respectively. Thus, interaction at muscarinic sites would occur only with large doses of these drugs. In contrast, the ratios were low for pancuronium and gallamine, 5.3 and 2.4, respectively. Hence, the concentrations of these drugs needed for clinical neuromuscular blockade would occupy appreciable fractions of cardiac muscarinic receptors, and thus might produce vagal blockade and thereby produce the tachycardia seen clinically with these two agents.
测定了四种神经肌肉阻滞剂在心脏起搏器以及运动终板处的药物受体解离常数（KB）。发现d - 筒箭毒碱和二甲基筒箭毒碱的KB（心房）/KB（蚓状肌）比值较高，分别为264和136。因此，只有大剂量使用这些药物时才会与毒蕈碱位点发生相互作用。相比之下，泮库溴铵和加拉明的比值较低，分别为5.3和2.4。因此，临床神经肌肉阻滞所需的这些药物浓度会占据相当一部分心脏毒蕈碱受体，从而可能导致迷走神经阻滞，进而产生临床上这两种药物所见的心动过速。
