title: A radioimmunoassay for plasma dehydroepiandrosterone sulphate incorporating placental steroid sulphatase as a hydrolysing reagent.
abstract: We describe a method for the measurement of plasma dehydroepiandrosterone sulphate (DHAS) which incorporates a Triton X-100 solubilised preparation of human placental steroid sulphatase as a hydrolysing agent and a direct radioimmunoassay of liberated DHA using a specific antiserum. The hydrolysis procedure is carried out at 50 degrees C for 1 h and an assay run can be completed in 4 h. As determined by the method, plasma concentrations of DHAS in 32 normal adult men (ages 23-58 yr) had a mean value +/- SD of 5.5 +/- 1.89 mumol/l. For 30 normal adult cyclic women (ages 22-35 yr) the mean plasma concentration of DHAS +/- SD was 3.1 +/- 1.35 mumol/l which was significantly lower (P less than 0.01) than found for men. Plasma DHAS concentration were also measured in 50 hirsute female patients. The mean value +/- SD was 5.03 +/- 2.52 mumol/l which was significantly higher (P less than 0.01) than the value for the normal female group. Some 42% of the hirsute patients had DHAS concentrations above the upper 95% probability limit of the normal range for premenopausal women.
mesh_terms: D000328:Adult; D003687:Dehydroepiandrosterone / Q000031:analogs & derivatives* / Q000097:blood; D019314:Dehydroepiandrosterone Sulfate; D005260:Female; D006628:Hirsutism / Q000097:blood; D006801:Humans; D006868:Hydrolysis; D007202:Indicators and Reagents; D008297:Male; D008875:Middle Aged; D010920:Placenta / Q000201:enzymology*; D011863:Radioimmunoassay; D043266:Steryl-Sulfatase; D013429:Sulfatases / Q000378:metabolism*
chemical_list: D007202:Indicators and Reagents; D003687:Dehydroepiandrosterone; D019314:Dehydroepiandrosterone Sulfate; D013429:Sulfatases; D043266:Steryl-Sulfatase