Functional Measurement of CYP2C9 and CYP3A4 Allelic Polymorphism on Sildenafil Metabolism.

摘要: Aim We aimed to systematically examine the effects of enzymatic activity 38 human CYP2C9 alleles and 21 CYP3A4 alleles, including wild-type CYP2C9.1 CYP3A4.1, which contain 24 novel (*36–*60) 6 (*28–*34) newly found in Chinese population, on sildenafil metabolism through vitro experiment. Methods The recombinant cytochrome P450 protein expressed insect baculovirus expression system were reacted with 10–500 µM for 30 minutes at 37°C, reaction was terminated by cooling −80°C immediately. Next, we used ultra-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) detection detect its active metabolite N-desmethyl sildenafil. Results intrinsic clearance (Vmax/Km) values most variants significantly altered when compared CYP2C9*1, these exhibiting either reduced Vmax and/or increased Km values. Four (CYP2C9*11, *14, *31, *49) exhibited no markedly decreased relative (1-fold). remaining thirty-three decrease different levels, ranging from 1.81% 88.42%. For metabolic pathway, CYP3A4*1, four (CYP3A4*3, *10, *14 *I335T) showed higher (130.7–134.9%), while five (CYP3A4*2, *5, *24, *L22V *F113I) sharply (1.80–74.25%), nine allelic statistical difference. In addition, kinetic parameters two (CYP3A4*17 CYP3A4*30) could not be detected, due defect gene. Conclusion These findings first evaluation all infrequent metabolism; treating people who carry variants, there should more focus relation dose intensity, side therapeutic efficacy administering sildenafil. study will provide fundamental data effect variation further clinical research.