Dehydroepiandrosterone sulfate in plasma: hydrolysis, extraction and radioimmunoassay

At pH 4.5, the hydrolysis of 3beta-hydroxy-5-androsten-17-one 3-sulfate (DHA-SO4) to DHA was complete within 75 min at 120 degrees or 4h at 100 degrees. In the same conditions, the 3alpha-SO4 of androsterone was stable, and only 8.5% of the 3beta-SO4 of epiandrosterone hydrolysed to epiandrosterone. Of the sulfates of 5-androstene-3beta, 17beta-diol, 100% of the 3beta-mono-SO4, 2% OF THE 17BETA-MONO-SO4 and none of the 3beta, 17beta-di-SO4 was converted to 5-androstenediol. Denatured plasma proteins adsorbed DHA. The recovery of DHA from plasma diluted 1:100, 58.7 +/- 6.2% (mean +/- S.D.). In similar conditions the recovery of cholesterol from plasma diluted 1:20, was 0.12 - 1.76% (mean, 0.44%). A radioimmunoassay for DHA in extracts of hydrolysed plasma is described. Results for normal subjects in the age range 17-45y were 192 +/- 73mug/dl (22 men) and 158 +/- 57mug/dl (40 women).