Saita Tetsuya, Fujito Hiroshi, Mori Masato
Faculty of Hospital Pharmacy, Saga Medical School, 5-1-1 Nabeshima, Saga 849-8501, Japan.
Biol Pharm Bull. 2003 Jun;26(6):761-5. doi: 10.1248/bpb.26.761.
This paper reports a sensitive and specific enzyme-linked immunosorbent assay for determination of the antiarrhythmic drug mexiletine in human serum. Anti-mexiletine antibody was obtained by immunizing rabbits with an antigen conjugated with mercaptosuccinyl bovine serum albumin using N-(epsilon-maleimidocaproyloxy)succinimide as a heterobifunctional coupling agent. Enzyme labeling of mexiletine with beta-D-galactosidase was performed using glutaraldehyde. In this assay, the mexiletine to be quantified is chemically modified by acetic anhydride allowed to compete with a mexiletine-beta-D-galactosidase conjugate for binding to a limited amount of an anti-mexiletine antibody which was used to coat the wells of a microtiter plate. Mexiletine concentrations lower than 80 ng/ml were measurable reproducibly by the enzyme-linked immunosorbent assay. This assay was specific for mexiletine and showed very slight cross-reactivity with its major metabolite, 2-hydroxymethylmexiletine (1.5%), but none with p-hydroxymexiletine. The values of serum mexiletine levels from 15 patients by this enzyme-linked immunosorbent assay were comparable with those measured by HPLC. There was a good correlation between the values determined by the two methods. The enzyme-linked immunosorbent assay should be a valuable tool in therapeutic drug monitoring and pharmacokinetic studies of mexiletine.
本文报道了一种灵敏且特异的酶联免疫吸附测定法，用于测定人血清中的抗心律失常药物美西律。使用N-(ε-马来酰亚胺己酰氧基)琥珀酰亚胺作为异双功能偶联剂，将与巯基琥珀酰牛血清白蛋白偶联的抗原免疫兔子，从而获得抗美西律抗体。使用戊二醛对美西律与β-D-半乳糖苷酶进行酶标记。在该测定法中，待定量的美西律经乙酸酐化学修饰后，与美西律-β-D-半乳糖苷酶偶联物竞争结合包被在微量滴定板孔中的有限量抗美西律抗体。酶联免疫吸附测定法可重复测量低于80 ng/ml的美西律浓度。该测定法对美西律具有特异性，与其主要代谢物2-羟甲基美西律的交叉反应性非常低（1.5%），与对羟基美西律无交叉反应。通过该酶联免疫吸附测定法测得的15例患者血清美西律水平值与通过高效液相色谱法测得的值相当。两种方法测定的值之间具有良好的相关性。酶联免疫吸附测定法应是美西律治疗药物监测和药代动力学研究中的一种有价值的工具。
