Eglen R M, Whiting R L
Syntex Research, Palo Alto, CA 94303.
Life Sci. 1989;44(1):81-94. doi: 10.1016/0024-3205(89)90221-x.
We have studied problems associated with the application of the Cheng-Prusoff relationship to the estimation of atropine dissociation constants from isolated guinea-pig tracheal responses. The values obtained have been compared to dissociation constants derived using Schild analysis. It was observed that when either carbachol (an agonist of high efficacy) or pilocarpine (an agonist of low efficacy) was used the dissociation constants estimated for atropine using the Schild analysis were very similar to those estimated using the Cheng-Prusoff relationship. In these latter experiments the agonist concentration used was the EC80. When the agonist concentration used was increased to supramaximal concentrations (3-fold greater than the EC100) the dissociation constants derived were overestimations by approximately 10-fold. It is concluded that in certain circumstances the results obtained using both the Cheng-Prusoff relationship and Schild analysis are comparable. However, it is unlikely that the Cheng-Prusoff relationship is generally applicable and that Schild analysis is clearly preferable in determining antagonist dissociation constants.
我们研究了将程-普鲁索夫关系应用于从豚鼠离体气管反应估计阿托品解离常数时相关的问题。已将所得值与使用希尔德分析得出的解离常数进行了比较。观察到，当使用卡巴胆碱（一种高效激动剂）或毛果芸香碱（一种低效激动剂）时，使用希尔德分析估计的阿托品解离常数与使用程-普鲁索夫关系估计的解离常数非常相似。在这些后期实验中，使用的激动剂浓度为EC80。当使用的激动剂浓度增加到超最大浓度（比EC100大3倍）时，得出的解离常数被高估了约10倍。结论是，在某些情况下，使用程-普鲁索夫关系和希尔德分析获得的结果具有可比性。然而，程-普鲁索夫关系不太可能普遍适用，并且在确定拮抗剂解离常数方面，希尔德分析显然更可取。
