A radioimmunoassay for serum dehydroepiandrosterone sulfate

• Published in: Steroids Vol. 20; no. 6; pp. 813 - 824
• Main Authors: Hisahiko, Sekihara, Nakaaki, Ohsawa, Hiroshi, Ibayashi
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.12.1972
• Subjects: Adrenal Gland Diseases - blood; Adult; Animals; Antibody Specificity; Chromatography, Gas; Chromatography, Thin Layer; Dehydroepiandrosterone - blood; Female; Humans; Male; Methods; Middle Aged; Oximes - chemical synthesis; Rabbits - immunology; Radioimmunoassay; Serum Albumin, Bovine; Sulfates - blood; Tritium
• ISSN: 0039-128X; 1878-5867
• DOI: 10.1016/0039-128X(72)90059-1

A radioimmunoassay for serum dehydroepiandrosterone sulfate (DHEAS) (1) has been developed using anti-DHEA antiserum obtained by immunizing rabbits with DHEA-17 oxime-bovine serum albumin. Serum volume of 0.01 to 0. 1 ml was used for analysis. After the addition of ammonium salt of DHEA-7α 3 H sulfate for recovery and a preliminary removal of DHEA, DHEAS was extracted as pyridinium salt by methylene chloride. The dried extract was subjected to solvolysis (Burstein & Lieberman), followed by paper chromatography. The eluates and DHEA-7 α 3H which was added to determine the % free of DHEA were evaporated and incubated with the antiserum containing pepsin treated human immune serum globulin and bovine serum albumin at 37°C for 1 hour. Ammonium sulfate was used to separate free from bound DHEA. The accuracy, precision and specificity were satisfactory. The sensitivity was 3 ng per sample. The blank values could not be differentiated from zero. Although the antiserum reacts with the other 3βOHΔ 5 steroids as well as DHEA, the complete separation of DHEA from the other 3βOHΔ 5 steroids was achieved chromatographically. Serum DHEAS levels in normal subjects and patients with adrenocortical disorders obtained with the radioimmunoassay were comparable to those obtained with gasliquid chromatography.