Wolford S T, Argoudelis C J
J Dairy Sci. 1979 Sep;62(9):1458-63. doi: 10.3168/jds.S0022-0302(79)83446-3.
Free natural estrogens in raw and commercial whole milk were quantitated by radioimmunoassay. The ranges of concentration of estrone, estradiol 17-beta, and estriol were 34 to 55, 4 to 14, and 9 to 31 pg/ml. Proportions of active estrogens (estrone and estradiol) in the fat phases of milk by radioactive tracer on separated milk were 80% and 65%. These findings were supported by radioimmunoassay of skim milk and butter. Equilibrium dialysis of skim milk with hydrogen 3 labeled estrogens showed that 84 to 85% of estrone and estradiol and 61 to 66% of estriol were protein bound. Whey proteins demonstrated a greater binding capacity than casein. This result was confirmed by radioimmunoassay of dry curd cottage cheese and whey. The concentrations in curd were 35, 11, and 6 pg/g. In whey they were 4, 2, and 3 pg/ml. The quantity of active estrogens in dairy products is too low to demonstrate biological activity. Butter was highest with concentrations of 539, 82, and 87 pg/g. Human colostrum demonstrated a maximum concentration of 4 to 5 ng/ml for estrone and estriol and about .5 ng/ml for estradiol. By the 5th day postpartum, they decreased to become similar to cow's milk.
采用放射免疫分析法对生鲜全脂牛奶和市售全脂牛奶中的游离天然雌激素进行定量分析。雌酮、17-β-雌二醇和雌三醇的浓度范围分别为34至55皮克/毫升、4至14皮克/毫升和9至31皮克/毫升。通过对分离出的牛奶进行放射性示踪，发现牛奶脂肪相中活性雌激素（雌酮和雌二醇）的比例分别为80%和65%。脱脂牛奶和黄油的放射免疫分析结果支持了这些发现。用³H标记的雌激素对脱脂牛奶进行平衡透析表明，84%至85%的雌酮和雌二醇以及61%至66%的雌三醇与蛋白质结合。乳清蛋白的结合能力比酪蛋白更强。凝乳干酪和乳清的放射免疫分析证实了这一结果。凝乳中的浓度分别为35皮克/克、11皮克/克和6皮克/克。乳清中的浓度分别为4皮克/毫升、2皮克/毫升和3皮克/毫升。乳制品中活性雌激素的含量过低，无法显示出生物活性。黄油中的含量最高，浓度分别为539皮克/克、82皮克/克和87皮克/克。人初乳中雌酮和雌三醇的最高浓度为4至5纳克/毫升，雌二醇约为0.5纳克/毫升。产后第5天，它们的浓度下降，与牛奶中的浓度相似。
