Phenotyping of cytochrome P450 3A enzymes in individual cynomolgus monkeys by endogenous compounds in plasma determined by liquid chromatography-mass spectrometry

Abstract

Recently, the endogenous compounds 4β-hydroxycholesterol (4β-OH-CHO) and 6β-hydroxycortisol (6β-OH-COR) have been found to be biomarkers of CYP3A in human and monkey. In this study, we developed a method for determining 4β-OH-CHO, cholesterol, 6β-OH-COR, and cortisol concentrations in monkey plasma. After a sensitive LC-MS/MS method was developed and validated, the individual monkey plasma was measured. We will introduce information on the endogenous biomarkers of CYP3A activity in individual monkey plasma and discuss basic information on this evaluation method.