Miyachi Y, Ishihara M, Kurihara S, Yoshida M, Masuda H, Komuro M, Taira K, Kawaguchi Y
First Department of Internal Medicine, Toho University School of Medicine, Tokyo, Japan.
Steroids. 1988 Jul-Aug;52(1-2):137-53. doi: 10.1016/0039-128x(88)90222-x.
A sensitive radioimmunoassay for dexamethasone 17,21-dipropionate and its four metabolites in human plasma and urine has been developed using single anti-dexamethasone antiserum. The antiserum was obtained by immunizing rabbits with dexamethasone-3-oxime-bovine serum albumin conjugate. All of the endogenous steroids tested cross-reacted less than 0.07%. Before radioimmunoassay, dexamethasone 17,21-dipropionate and dexamethasone 17-propionate were hydrolyzed to dexamethasone, and 6 beta-OH-dexamethasone 17-propionate was hydrolyzed to 6 beta-OH-dexamethasone in 3% ammonia/methanol at 5 C for 16 h. A standard curve was established with a useful range between 0.005 and 2 ng in the case of dexamethasone, between 0.05 and 5 ng in the case of 6 beta-OH-dexamethasone. Measurement of plasma concentrations and percent urinary excretion of the metabolites in healthy men was performed following occlusive dressing of dexamethasone 17,21-dipropionate cream and ointment. The main metabolites in plasma were dexamethasone 17-propionate and dexamethasone, which increased gradually and reached maximum levels (160-200 pg/mL) at 24-32 h after application. The major metabolites observed in urine were 6 beta-OH-dexamethasone 17-propionate and 6 beta-OH-dexamethasone. Total percentage of their urinary excretions within 72 h after application amounted to 0.28-0.50% of the dose administered.
已利用单克隆抗地塞米松抗血清开发出一种灵敏的放射免疫分析法，用于检测人血浆和尿液中的地塞米松17,21 - 二丙酸酯及其四种代谢物。该抗血清是通过用地塞米松 - 3 - 肟 - 牛血清白蛋白偶联物免疫兔子获得的。所有检测的内源性甾体的交叉反应率均低于0.07%。在进行放射免疫分析之前，将地塞米松17,21 - 二丙酸酯和地塞米松17 - 丙酸酯在5℃下于3%氨/甲醇中水解16小时，使其转化为地塞米松，将6β - 羟基 - 地塞米松17 - 丙酸酯水解为6β - 羟基 - 地塞米松。以地塞米松为例，建立的标准曲线的有效范围在0.005至2纳克之间；以6β - 羟基 - 地塞米松为例，有效范围在0.05至5纳克之间。在局部封闭敷用地塞米松17,21 - 二丙酸酯乳膏和软膏后，对健康男性的血浆浓度和代谢物的尿排泄百分比进行了测定。血浆中的主要代谢物是地塞米松17 - 丙酸酯和地塞米松，它们逐渐增加，并在用药后24 - 32小时达到最高水平（160 - 200皮克/毫升）。尿液中观察到的主要代谢物是6β - 羟基 - 地塞米松17 - 丙酸酯和6β - 羟基 - 地塞米松。用药后72小时内它们的尿排泄总量占给药剂量的0.28 - 0.50%。
