Heterologous enzyme immunoassay for serum androstenediol.

A heterologous enzyme immunoassay for serum androstenediol (Adiol: 3beta, 17beta-dihydroxy-androst-5-ene) was established. The combination of anti-Adiol antiserum raised in rabbit against Adiol 7-O-(carboxymethyl)oxime (Adiol 7-CMO) conjugated bovine serum albumin (Adiol 7-CMO-BSA) and Adiol 7-iminomethylcarboxylic acid conjugated alkaline phosphatase was used for the assay. The sensitivity of the heterologous assay system was superior to that of a homologous assay system in which an antibody raised in rabbit against Adiol 7-CMO-BSA and enzyme labeled antigen, Adiol 7-CMO conjugated alkaline phosphatase, were used. The minimal amount of Adiol detected was 0.4 ngml(-1) and the measurable range was from 0. 4 to 150 ngml(-1). Intra-assay coefficients of variation (C.V.) were 8.6% (1.52+/-0.13 ngml(-1), mean+/-S.D., n=10) and 6.7% (13.4+/-0.9 ngml(-1), n=10). Inter-assay C.V. were 12.9% (1.63+/-0.21 ngml(-1), n=8) and 11.5% (12.2+/-1.4 ngml(-1), n=8). A linear relation was observed between the serum sample dilution and the Adiol concentration. For recovery study, authentic Adiol was added to serum sample (original concentration: 1.43 ngml(-1)). The calculated final Adiol concentration was 2.99 ngml(-1). The recovery was 98.6% (n=5). The Adiol concentrations in healthy subjects measured by the proposed assay (male: 1.1+/-0.3 ngml(-1) (mean+/-S.D.), range: 0.7-1. 7 ngml(-1), age: 22-50, n=10; female: 0.6+/-0.4 ngml(-1), range: 0. 2-1.6 ngml(-1), age: 23-48, n=20) were consistent with reported values.

Serum dehydroepiandrosterone, dehydroepiandrosterone sulfate, and pregnenolone sulfate concentrations in patients with hyperthyroidism and hypothyroidism.

BACKGROUND: Dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEA-S) have been suggested to have protective effects against cardiovascular disease, cancer, immune-modulated diseases, and aging. We examined serum concentrations of DHEA, DHEA-S, and pregnenolone sulfate (PREG-S) in patients with thyroid dysfunction. METHODS: Steroids extracted with methanol from serum sample were separated into an unconjugated fraction (DHEA) and a monosulfate fraction (DHEA-S and PREG-S), using a solid-phase extraction and an ion-exchange column. After separation of unconjugated steroids by HPLC, the DHEA concentration was measured by enzyme immunoassay. The monosulfate fraction was treated with arylsulfatase, and the freed steroids were separated by HPLC. The DHEA and PREG fractions were determined by gas chromatography-mass spectrometry, and the concentrations were converted into those of DHEA-S and PREG-S. RESULTS: Serum concentrations of DHEA, DHEA-S, and PREG-S were all significantly lower in patients with hypothyroidism (n = 24) than in age- and sex-matched healthy controls (n = 43). By contrast, in patients with hyperthyroidism (n = 22), serum DHEA-S and PREG-S concentrations were significantly higher, but the serum DHEA concentration was within the reference interval. Serum concentrations of these three steroids correlated with serum concentrations of thyroid hormones in these patients. Serum albumin and sex hormone-binding globulin concentrations were not related to these changes in the concentration of steroids. CONCLUSIONS: Serum concentrations of DHEA, DHEA-S, and PREG-S were decreased in hypothyroidism, whereas serum DHEA-S and PREG-S concentrations were increased but DHEA was normal in hyperthyroidism. Thyroid hormone may stimulate the synthesis of these steroids, and DHEA sulfotransferase might be increased in hyperthyroidism.