羟氯喹在人肝微粒体CYP酶中的代谢研究

目的：探讨羟氯喹在人肝微粒体中的主要代谢酶及其代谢特点和参数。方法：建立高效液相色谱-荧光检测器（HPLC-FLD）测定孵育液中羟氯喹的方法，观察9种CYP酶特异性抑制剂对羟氯喹代谢的影响，计算羟氯喹的酶促动力学参数如米氏常数（Km）、最大反应速度（Vmax）和药物的内在清除率（CLint）。结果：9种酶抑制剂中孟鲁司特（CYP2CB抑制剂）、酮康唑（CYP3A4抑制剂）、噻氯匹定（CYP2B6抑制剂）能够显著抑制羟氯喹的代谢（P ＜ 0.05）。羟氯喹在人肝微粒体中Vmax为233.6 ng·mL-1·h-1·mgprotein-1，Km为14.5 ng·mL-1，CLint为16.2 h-1·mgprotein-1。结论：羟氯喹主要通过CYP2C8、CYP3A4和CYP2B6代谢，药物在体内清除速率慢，药物相互作用和蓄积是发生不良反应的重要因素。

Enzyme Kinetics Research of Hydroxychloroquine in Human Liver Microsomal CYP Enzymes

Objective: To investigate the metabolic characteristics and enzymes of hydroxychloroquine in human liver microsomes. Method: An HPLC-FLD method was used to determine the concentrations of hydroxychloroquine in incubation liquids. Changes of hydroxychloroquine metabolism were observed with 9 CYP subtype specific inhibitors. Enzymatic dynamics study of hydroxychloroquine was also calculated to deduce drug Michaelis constant (Km), maximum reaction rate (Vmax) and drug clearance (CLint) in vitro. Results: Among the 9 inhibitors, ketoconazole, montelukast and ceclopyridine significantly inhibited the metabolism of hydroxychloroquine. The values of Km, Vmax and CLint of hydroxychloroquine in hepatic microsomes were 233.6 ng·mL-1·h-1·mgprotein-1, 14.5 ng·mL-1 and 16.2 h-1·mgprotein-1, respectively. Conclusion: Hydroxychloroquine is mainly metabolized by CYP2C8, CYP3A4 and CYP2B6. The rate of drug clearance is slow. As a result, drug interaction and accumulation are important factors for adverse effects.