Radioimmunoassay for 11-deoxycortisol using iodine-labeled tracer.
A simple and sensitive radioimmunoassay for 11-deoxycortisol was developed. The antiserum produced in rabbits by immunizing with a complex of 11-deoxycortisol-3-oxime and bovine serum albumin (BSA) has little cross-reactivity with other endogenous steroids. The immunoassay procedure requires only one-step ethanol denaturation of binding proteins in plasma and extraction by an organic solvent can be omitted. Furthermore, use of 125I-labeled tracer significantly simplify the counting procedure. The method is sensitive enough to detect 1 microng/100 ml of 11-deoxycortisol. Plasma 11-deoxycortisol levels measured by this method after the administration of a single dose of metyrapone ranged from 5.0 to 19.2 microng/100 ml, whereas they were 0 to 4.0 microng/100 ml in hypopituitary patients. It is concluded that this simple method is useful for the routine assay of plasma 11-deoxycortisol as a parameter of the metyrapone tests.
D015065:17-Hydroxycorticosteroids / Q000097:blood*; D003350:Cortodoxone / Q000097:blood*; D003429:Cross Reactions; D005069:Evaluation Studies as Topic; D006801:Humans; D007018:Hypopituitarism / Q000097:blood; D007457:Iodine Radioisotopes; D008297:Male; D008797:Metyrapone / Q000008:administration & dosage; D011863:Radioimmunoassay / Q000379:methods*
D015065:17-Hydroxycorticosteroids; D007457:Iodine Radioisotopes; D003350:Cortodoxone; D008797:Metyrapone