Development of a radioreceptor assay to measure glucocorticoids.
We have developed a radioreceptor assay to measure glucocorticoids. The assay employs the partially purified 95-kDa receptor isolated from human liver and purified by size fractionation on high-performance liquid chromatography (HPLC). In the assay [3H]prednisolone competes with steroids (endogenous and exogenous) for binding to the receptor. Bound and free are separated by treatment with charcoal. The between-day precision [% coefficient of variation (CV)] at concentrations of 9.4, 18.7, and 69.9 micrograms/L prednisolone is 16.6, 9.3 and 4.5%, respectively. Specificity studies revealed that hydrocortisone, deoxycorticosterone, 4-pregnene-17 alpha,21-diol-3,20-dione, 17 alpha-hydroxyprogesterone, corticosterone and beta-hydroxyprogesterone all compete with [3H]prednisolone for binding to the receptor. Prednisone and 6 alpha-methyl prednisolone displace [3H]prednisolone to only a minor degree. The assay has been used to assess "glucocorticoid activity" in children with rheumatic diseases treated with prednisolone.
Soldin
S J
SJ
Department of Laboratory Medicine, Children's National Medical Center, Washington, DC 20010.
Rifai
N
N
Palaszynski
E W
EW
Morales
A
A
Lipnick
R N
RN
D002606:Charcoal; D003429:Cross Reactions; D003600:Cytosol / Q000737:chemistry; D005938:Glucocorticoids / Q000032:analysis* / Q000097:blood; D006801:Humans; D007202:Indicators and Reagents; D008099:Liver / Q000737:chemistry; D011239:Prednisolone / Q000032:analysis; D011869:Radioligand Assay / Q000379:methods*; D012216:Rheumatic Diseases / Q000097:blood / Q000378:metabolism
D005938:Glucocorticoids; D007202:Indicators and Reagents; D002606:Charcoal; D011239:Prednisolone