Swanson B N, Stauber K L, Alpaugh W C, Weinstein S H
Anal Biochem. 1985 Aug 1;148(2):401-7. doi: 10.1016/0003-2697(85)90245-3.
A rapid, sensitive assay for angiotensin-converting enzyme (ACE) inhibitors is described. Biological samples were diluted with methanol to precipitate endogenous ACE and centrifuged. Supernatants were further diluted with 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid buffer, pH 8. Diluted samples were incubated at 37 degrees C with the substrate [3H]hippurylglycylglycine and rabbit lung ACE for 45 min. Acid (1.0 N HCl) was then added, and the product, [3H]hippuric acid, was extracted into a water-immiscible scintillation cocktail. Drug standards were prepared in the biological matrix to correct for drug recovery. A computer program was used to convert radioactivity (dpm) to units of enzyme activity and then correlate enzyme activity with drug concentration. The ester prodrugs fosenopril and enalapril could be assayed down to 4 ng/ml in plasma after ester hydrolysis with NaOH. Drug disposition studies in rats, dogs, and monkeys have demonstrated that the method can be readily adapted to any ACE inhibitor and is suitable for determining drug bioavailability and pharmacokinetics.
本文描述了一种快速、灵敏的血管紧张素转换酶（ACE）抑制剂检测方法。生物样品用甲醇稀释以沉淀内源性ACE，然后离心。上清液用pH 8的4-（2-羟乙基）-1-哌嗪乙磺酸缓冲液进一步稀释。稀释后的样品在37℃下与底物[3H]马尿酰甘氨酰甘氨酸和兔肺ACE孵育45分钟。然后加入酸（1.0 N HCl），产物[3H]马尿酸被萃取到与水不混溶的闪烁液中。在生物基质中制备药物标准品以校正药物回收率。使用计算机程序将放射性（dpm）转换为酶活性单位，然后将酶活性与药物浓度相关联。用氢氧化钠进行酯水解后，血浆中福辛普利和依那普利酯前药的检测下限可达4 ng/ml。在大鼠、狗和猴子身上进行的药物处置研究表明，该方法可轻松适用于任何ACE抑制剂，适用于测定药物生物利用度和药代动力学。
