Schalm S W, Summerskill W H, Go V L
Mayo Clin Proc. 1976 Dec;51(12):761-6.
Radioimmunoassays for measuring prednisone and prednisolone (delta1 corticosteroids) in serum have been developed. By using 6,7-3H-delta1 corticosteroids as tracer, rabbit antibodies against delta1 corticosteroid-21-hemisuccinate in bovine serum albumin, and ammonium sulfate precipitation, the assays detected less than 0.8 ng/ml of delta1 corticosteroid and interassay coefficients of variation were less than 8.5 %. The specificity of antibodies, tested against all drug metabolites and major endogenous steroids, showed that only 21-glucuronic acid esters of delta1 corticosteroids had cross-reactivity of possible clinical importance. Assays were validated by measuring levels in samples of fastingstate sera with or without adding known amounts of prednisolone. Measurements of serum concentrations of both prednisone and prednisolone in normal dogs and in those with hepatic vascular exclusion were made after intravenous administration of prednisone. Although high levels of prednisolone appeared rapidly in normal dogs, only slight amounts were measured in dogs with hepatic vascular exclusion, which emphasized the importance of the liver in the conversion of prednisone to prednisolone, its active metabolite.
已开发出用于测定血清中泼尼松和泼尼松龙（δ1皮质类固醇）的放射免疫测定法。通过使用6,7-3H-δ1皮质类固醇作为示踪剂、针对牛血清白蛋白中δ1皮质类固醇-21-半琥珀酸酯的兔抗体以及硫酸铵沉淀法，该测定法可检测到低于0.8 ng/ml的δ1皮质类固醇，测定间变异系数小于8.5%。针对所有药物代谢物和主要内源性类固醇进行测试的抗体特异性表明，只有δ1皮质类固醇的21-葡萄糖醛酸酯具有可能具有临床重要性的交叉反应性。通过测量添加或不添加已知量泼尼松龙的空腹状态血清样本中的水平来验证测定法。在静脉注射泼尼松后，对正常犬和肝血管阻断犬的血清泼尼松和泼尼松龙浓度进行了测量。尽管正常犬体内迅速出现高浓度的泼尼松龙，但在肝血管阻断犬中仅检测到少量，这强调了肝脏在将泼尼松转化为其活性代谢物泼尼松龙过程中的重要性。
