Aim: To investigate the distribution of genotype of CYP3AP1 in Chinese Han population and the correlation with CYP3A activity.
Methods: Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was employed in CYP3AP1 genotype analysis; using midazolam as probe drug, CYP3A activity of 191 Chinese healthy subjects was measured by plasma 1'-hydroxymidazolam/midazolam (1'-OH-MDZ/MDZ) ratio at 1 h after oral administration of 7.5 mg midazolam.
Results: There was significant difference of CYP3A activity in different genotypes of CYP3AP1 in vivo (P <0.05). The activity of CYP3A in homozygous A(-44) (CYP3AP1*3/CYP3AP1*3) is lower than heterozygous A(-44)G (CYP3AP1*1/CYP3AP1*3), and the CYP3A activity in homozygous G(-44) (CYP3AP1*1/CYP3AP1*1) is t he highest.
Conclusion: There was association between the genotype of CYP3AP1 and increased activity of CYP3A in vivo.