Munson P J, Rodbard D
Laboratory of Theoretical and Physical Biology, National Institute of Child Health and Human Development, Bethesda, Md 20892.
J Recept Res. 1988;8(1-4):533-46. doi: 10.3109/10799898809049010.
The use of graphical estimation techniques in pharmacology is well entrenched, yet can sometimes lead to confusion and errors. The widely used Cheng-Prusoff correction for obtaining the inhibition constant Ki from the graphical mid point or ED50 of a displacement or inhibition curve is not exact, contrary to popular belief. We show that under many commonly used experimental conditions, the Cheng-Prusoff rule can lead to a substantial 3- to 6-fold or larger error in the estimate of Ki. Surprisingly, an explicit, relatively simple exact correction rule is available. We derive this rule and show the conditions under which its use is required.
药理学中图形估计技术的应用已相当成熟，但有时也会导致混淆和错误。与普遍看法相反，广泛用于从位移或抑制曲线的图形中点或ED50获取抑制常数Ki的Cheng-Prusoff校正并不精确。我们表明，在许多常用的实验条件下，Cheng-Prusoff规则可能会导致Ki估计值出现高达3至6倍或更大的显著误差。令人惊讶的是，有一个明确、相对简单的精确校正规则。我们推导了这个规则，并展示了需要使用它的条件。
