[Specific radioimmunoassay and physiological significance of unconjugated 2-hydroxyestrone and 2-hydroxyestradiol-17 beta in human blood (author's transl)].

Recently it has been attached importance to the physiological function of catecholestrogens. To elucidate it a specific radioimmunoassay of conjugated 2-hydroxyestrone (2-OHE1) and 2-hydroxyestradiol-17 beta (2-OHE2) in human plasma was attempted. After extracting with ethyl acetate, samples were purified by a short Sephadex LH-20 columnchromatography and determined using the antiserum to 2-OHE1-17(O-carboxymethyl) oxime-bovine serum albumin conjugate. The following results were obtained: 1) A long Sephadex LH-20 columnchromatography which was used for the purification of catecholestrogens produced chemically, had a superior faculty in separation and high capacity 2) The antiserum cross-reacted 26.4% with 1-OHE2, but less than 1% with other steroid hormones. 3) The sensitivity of the method was around 10pg in both 2-OHE1 and 2-OHE2 assays. The method blank determined using 2ml plasma of bilaterally adreno-oophrectomized women was below 15 pg/ml in both 2-OHE1 and 2-OHE2 assays (n = 24). 4) The coefficient of variation in both accuracy and between-assay precision of the method was less than 17%. 5) The plasma 2-OHE1 concentration was below 15 pg/ml in normal men (n = 8) and non-pregnant women (n = 13). The concentration in pregnant women was 20 +/- 8 pg/ml (SD, n = 7) in 1st trimester of pregnancy, 58 +/- 13 (n = 3) in 2nd trimester and 177 +/- 66 (n = 12) in 3rd trimester. The E1/2-OHE1 and E2/2-OHE1 ratios in 3rd trimester of 9 pregnant women were 19.7 +/- 11.9(SD) and 78.0 +/- 27.8, respectively. 6) The plasma 2-OHE2 concentration was below 15 pg/ml in normal men (n = 8), non-pregnant women (n = 8), and 1st to 2nd trimester (n = 10) and 15 +/- 9 pg/ml (SD, n = 13) in 3rd trimester of pregnant women.