Marano M, Kaumann A J
J Pharmacol Exp Ther. 1976 Sep;198(3):518-25.
A linear relationship between equieffective concentrations of agonist in the presence and absence of partial agonist was examined statistically. These experimental concentrations permit the estimation of the apparent dissociation constant Kp with a weighted fit. The form of the weights was proposed theoretically and substantiated by simulated experiments. Constants Kp for (+/-)-p-chloroisoproterenol were estimated from the antagonism by three concentrations of (+/-)-p-chloroisoproterenol of the positive chronotropic effects of (-)-isoproterenol on kitten (Kp = 1.75 X 10(-7) M) and guinea-pig (Kp = 1.84 X 10(-7) M) right atria. The Kp values were similar regardless of the concentrations of (+/-)-p-chloroisoproterenol used; they were also similar to a Kp of 1.95 X 10(-7) M) estimated BY Kaumann and Birnbaumer (J. Biol. Chem. 249: 7874-7885, 1974) for the (+/-)-p-chloroisoproterenol-receptor complex coupled to the adenylyl cyclase in cell-free membrane particles of kitten heart. The proposed statistical procedure appears to be useful for systems with sigmoid log concentration-effect curves in which concentrations of the dependent variable are obtained from interpolation.
对存在和不存在部分激动剂时激动剂等效浓度之间的线性关系进行了统计学检验。这些实验浓度允许通过加权拟合来估计表观解离常数Kp。权重的形式是理论上提出的，并通过模拟实验得到证实。通过三种浓度的（±）-对氯异丙肾上腺素对（-）-异丙肾上腺素对小猫（Kp = 1.75×10^(-7) M）和豚鼠（Kp = 1.84×10^(-7) M）右心房正性变时作用的拮抗作用，估计了（±）-对氯异丙肾上腺素的Kp常数。无论使用的（±）-对氯异丙肾上腺素浓度如何，Kp值都相似；它们也与考曼和比尔瑙默（《生物化学杂志》249: 7874 - 7885, 1974）估计的1.95×10^(-7) M的Kp值相似，该值是针对与小猫心脏无细胞膜颗粒中的腺苷酸环化酶偶联的（±）-对氯异丙肾上腺素-受体复合物。所提出的统计程序似乎对具有S形对数浓度-效应曲线的系统有用，在该系统中，因变量的浓度是通过插值获得的。
