Radioimmunoassay for estimation of 11-deoxycortisol in plasma. Application for metopirone-test

A radioimmunoassay for the measurement of 11-deoxycortisol in plasma is described. Antiserum against 11-deoxycortisol was produced by immunizing rabbits with the 21-hemisuccinate of 11-deoxycortisol coupled to bovine serum albumin. The method does not require chromatography but instead makes use of a simple extraction procedure which, in combination with the antibody characteristics, is relatively specific for the 11-deoxycortisol determination. The smallest amount measurable is 5 pg. The intra-assay coefficient of variation was 6.3% before metopirone and 7.2% after metopirone. The inter-assay coefficient of variation was 12.5% before metopirone and 10.3% after metopirone. Pituitary-adrenal reserve was evaluted in control and hypopituitary subjects by a simple midnight metopirone test. (author)