Abstract
The oxidative metabolism of estradiol was studied in normal men and women by a radiometric procedure that provides information on the totality of the biotransformations concerned. The release of 3H into body water from estradiol labeled with 3H in the 17 alpha, 16 alpha, and C-2 positions permits measurement of the rate and extent of 17 beta-ol oxidation and of the competing hydroxylations at C-2 and 16 alpha, which lead to products with different biologicaly properties. In both men and women the 17 beta-ol oxidation is the most rapid transformation, followed by 2-hydroxylation and finally by 16 alpha-hydroxylation. Hydroxylation at C-2 predominates by a faccto of 2-4 over 16 alpha-hydroxylation. In men a large fraction (37%) of the substrate is unmetabolized at any of the three sites and is not excreted in urine; in women the corresponding fraction is only 18%. The estradiol fraction that does undergo metabolism is hydroxylated at C-2 vs. 16 alpha to a greater extent in women than in men. These major sex differences in the metabolism of estradiol in the human may have an important influence on the expression of the biological actions of the hormone. The radiometric technique used in this study can be generally applied to study the oxidative transformations of hormones, drugs, and other exogenous chemical that can be specifically labeled at reactive sites.
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Selected References
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- ADAMS J. A., JACOBSON H. I., LEVY H. R., TALALAY P. THE ESTROGENIC ACTIVITY AND ENZYMATIC OXIDATION OF 17-BETA-ESTRADIOL-17-ALPHA-D. Steroids. 1965;58:SUPPL 1–1:84. [PubMed] [Google Scholar]
- BRADLOW H. L., GALLAGHER T. F., HELLMAN L., ZUMOFF B. Interaction of hormonal effects: influence of triiodothyronine on androgen metabolism. Science. 1956 Dec 14;124(3233):1206–1207. doi: 10.1126/science.124.3233.1206-a. [DOI] [PubMed] [Google Scholar]
- Clark J. H., Paszko Z., Peck E. J., Jr Nuclear binding and retention of the receptor estrogen complex: relation to the agonistic and antagonistic properties of estriol. Endocrinology. 1977 Jan;100(1):91–96. doi: 10.1210/endo-100-1-91. [DOI] [PubMed] [Google Scholar]
- FISHMAN J., BRADLOW H. L., GALLAGHER T. F. Oxidative metabolism of estradiol. J Biol Chem. 1960 Nov;235:3104–3107. [PubMed] [Google Scholar]
- FISHMAN J., BRADLOW H. L., ZUMOFF B., HELLMAN L., GALLAGHER T. F. Further studies on the metabolism of oestradiol in man. Acta Endocrinol (Copenh) 1961 May;37:57–62. doi: 10.1530/acta.0.0370057. [DOI] [PubMed] [Google Scholar]
- FISHMAN J., BROWN J. B., HELLMAN L., ZUMOFF B., GALLAGHER T. F. Estrogen metabolism in normal and pregnant women. J Biol Chem. 1962 May;237:1489–1494. [PubMed] [Google Scholar]
- Fishman J. L., Boyar R. M., Hellman L. The system estradiol-estrone; a sex difference in oxidation of estradiol in man. J Clin Endocrinol Metab. 1972 Jun;34(6):989–996. doi: 10.1210/jcem-34-6-989. [DOI] [PubMed] [Google Scholar]
- Fishman J., Guzik H., Hellman L. Aromatic ring hydroxylation of estradiol in man. Biochemistry. 1970 Mar 31;9(7):1593–1598. doi: 10.1021/bi00809a018. [DOI] [PubMed] [Google Scholar]
- Fishman J., Hellman L., Zumoff B., Cassouto J. Pathway and stereochemistry of the formation of estriols in man. Biochemistry. 1966 Jun;5(6):1789–1794. doi: 10.1021/bi00870a003. [DOI] [PubMed] [Google Scholar]
- Fishman J., Yoshizawa I., Hellman L. Mechanism of catechol estrogen formation in man. Steroids. 1973 Sep;22(3):401–411. doi: 10.1016/0039-128x(73)90103-7. [DOI] [PubMed] [Google Scholar]
- GALLAGHER T. F., HELLMAN L., BRADLOW H. L., ZUMOFF B., FUKUSHIMA D. K. The effects of thyroid hormones on the metabolism of steroids. Ann N Y Acad Sci. 1960 Apr 23;86:605–611. doi: 10.1111/j.1749-6632.1960.tb42832.x. [DOI] [PubMed] [Google Scholar]
- Grodin J. M., Siiteri P. K., MacDonald P. C. Source of estrogen production in postmenopausal women. J Clin Endocrinol Metab. 1973 Feb;36(2):207–214. doi: 10.1210/jcem-36-2-207. [DOI] [PubMed] [Google Scholar]
- HELLMAN L., BRADLOW H. L., ZUMOFF B., FUKUSHIMA D. K., GALLAGHER T. F. Thyroid-androgen interrelations and the hypocholesteremic effect of androsterone. J Clin Endocrinol Metab. 1959 Aug;19:936–948. doi: 10.1210/jcem-19-8-936. [DOI] [PubMed] [Google Scholar]
- KAPPAS A., HELLMAN L., FUKUSHIMA D. K., GALLAGHER T. F. The pyrogenic effect of etiocholanolone. J Clin Endocrinol Metab. 1957 Mar;17(3):451–453. doi: 10.1210/jcem-17-3-451. [DOI] [PubMed] [Google Scholar]
- Kappas A. Biologic actions of some natural steroids on the liver. N Engl J Med. 1968 Feb 15;278(7):378–384. doi: 10.1056/NEJM196802152780707. [DOI] [PubMed] [Google Scholar]
- Martucci C. P., Fishman J. Impact of continuously administered catechol estrogens on uterine growth and luteinizing hormone secretion. Endocrinology. 1979 Dec;105(6):1288–1292. doi: 10.1210/endo-105-6-1288. [DOI] [PubMed] [Google Scholar]
- Martucci C., Fishman J. Direction of estradiol metabolism as a control of its hormonal action--uterotrophic activity of estradiol metabolites. Endocrinology. 1977 Dec;101(6):1709–1715. doi: 10.1210/endo-101-6-1709. [DOI] [PubMed] [Google Scholar]
- SANDBERG A. A., SLAUNWHITE W. R., Jr Studies on phenolic steroids in human subjects. II. The metabolic fate and hepato-biliary-enteric circulation of C14-estrone and C14-estradiol in women. J Clin Invest. 1957 Aug;36(8):1266–1278. doi: 10.1172/JCI103524. [DOI] [PMC free article] [PubMed] [Google Scholar]
- SCHLOERB P. R., FRIIS-HANSEN B. J., EDELMAN I. S., SOLOMON A. K., MOORE F. D. The measurement of total body water in the human subject by deuterium oxide dilution; with a consideration of the dynamics of deuterium distribution. J Clin Invest. 1950 Oct;29(10):1296–1310. doi: 10.1172/JCI102366. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schinfeld J. S., Tulchinsky D., Schiff I., Fishman J. Suppression of prolactin and gonadotropin secretion in post-menopausal women by 2-hydroxyestrone. J Clin Endocrinol Metab. 1980 Feb;50(2):408–410. doi: 10.1210/jcem-50-2-408. [DOI] [PubMed] [Google Scholar]
- Siiteri P. K., Williams J. E., Takaki N. K. Steroid abnormalities in endometrial and breast carcinoma: a unifying hypothesis. J Steroid Biochem. 1976 Nov-Dec;7(11-12):897–903. doi: 10.1016/0022-4731(76)90008-x. [DOI] [PubMed] [Google Scholar]
- Zumoff B., Fishman J., Cassouto J., Gallagher T. F., Hellman L. Influence of age and sex on normal estradiol metabolism. J Clin Endocrinol Metab. 1968 Jul;28(7):937–941. doi: 10.1210/jcem-28-7-937. [DOI] [PubMed] [Google Scholar]