Abstract
A simple and sensitive radioimmunoassay for 11-deoxycortisol was developped. 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 1μg/100ml 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 19.2μg/100ml, whereas they were 0 to 4.0μg/100ml 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.
