期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1977
卷号：74
期号：3
页码：941-945
DOI：10.1073/pnas.74.3.941
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Bovine adrenal cortical tissue contains a lipoidal derivative of pregnenolone (3beta-hydroxy-pregn-5-en-20-one) from which the free steroid can be liberated by treatment with alkali. Evidence for the presence of such an entity comes from examination of a nonpolar extract of tissue from which pregnenolone and its sulfate had been removed by chromatography. Treatment of the nonpolar fraction with alkali followed by exhaustive chromatographic analysis led to the detection of pregnenolone. The steroid was identified by both gas chromatography/mass spectrometry and double isotope procedures. Quantitative analysis indicated that the three forms of pregnenolone are present in bovine adrenal cortical tissue in the following amounts (mug/kg): lipoidal derivative, 290; free steroid, 435; and sulfate, 65. Because the only known metabolic function of pregnenolone is to serve as a precursor of the steroid hormones, these findings have far-reaching implications for steroid hormone biochemistry.
