This Article Full Text (PDF) Submit a related Letter to the Editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by FORNEY, J. P. Articles by MACDONALD, P. C. Search for Related Content PubMed PubMed Citation Articles by FORNEY, J. P. Articles by MACDONALD, P. C.

Aromatization of Androstenedione to Estrone by Human Adipose Tissue in Vitro. Correlation with Adipose Tissue Mass, Age, and Endometrial Neoplasia^*

Cecil H. and Ida Green Center for Reproductive Biology Sciences, and the Department of Obstetrics and Gynecology and Biochemistry, The University of Texas Southwestern Medical School at Dallas, Dallas, Texas 75235

Address correspondence and requests for reprints to: J. Peter Forney, M.D., Department of Obstetrics and Gynecology, The University of Texas Southwestern Medical School, 5323 Harry Hines Boulevard, Dallas, Texas 75235.

To explore the relationship between extraglandular estrogen formation and the clinical parameters of age, weight, and endometrial neoplasia, an assay was developed to measure the rate of estrogen formation from androgen precursors in human adipose tissue. The substrate, [³H]androstenedione, was more efficient than [³H]testosterone for the aromatase system in this tissue. The highest rate of conversion of androgen to estrogen occurred in tissue slices rather than in minces or microsomal preparations. The addition of cofactor NADPH was not required for aromatization in slices or minces, probably as a consequence of endogenous production of NADPH by the tissue. [³H]Estrone was the sole estrogenic product identified in incubations when [3H]androstenedione was used as the substrate, whereas [³H]estradiol-17/β was the exclusive estrogen detected when using [³H]testosterone. The rate of [³H]estrone formation from [³H]androstenedione in tissue slices was linear with time of incubation up to 2 h and with tissue mass up to 1.0 g. The optimal temperature for aromatase activity in these tissues was 37 C, and the apparent K_m of adipose tissue aromatase for androstenedione was 0.25 /µM. A method was also developed to measure DNA content in the tissue slices used for incubation. When the conversion rates of [³H]androstenedione to [³H]estrone and DNA content were measured in adipose tissue obtained from the abdominal wall of 48 women, 17 women with and 31 women without endometrial neoplasia, the rate of conversion of androstenedione to estrone per unit mass of adipose tissue (g) correlated significantly with calculated body component mass of adipose tissue as well as with calculated unit cell number (10⁶ cells) present in adipose tissue. There was no correlation with age. Moreover, the mean rate of estrone production in the adipose tissue obtained from women with endometrial hyperplasia or carcinoma was significantly higher than that obtained from equivalent weight women without endometrial neoplasia.

^* This work was supported in part by USPHS Grant PO1-HD11149

Received December 12, 1980.

This article has been cited by other articles:

				C M Friedenreich and A E Cust Physical activity and breast cancer risk: impact of timing, type and dose of activity and population subgroup effects Br. J. Sports Med., August 1, 2008; 42(8): 636 - 647. [Abstract] [Full Text] [PDF]

				N. Napoli, S. Donepudi, S. Sheikh, G. B. Rini, and R. Armamento-Villareal Increased 2-Hydroxylation of Estrogen in Women with a Family History of Osteoporosis J. Clin. Endocrinol. Metab., April 1, 2005; 90(4): 2035 - 2041. [Abstract] [Full Text] [PDF]

				G. A. Brown, M. D. Vukovich, E. R. Martini, M. L. Kohut, W. D. Franke, D. A. Jackson, and D. S. King Endocrine Responses to Chronic Androstenedione Intake in 30- to 56-Year-Old Men J. Clin. Endocrinol. Metab., November 1, 2000; 85(11): 4074 - 4080. [Abstract] [Full Text]

				B. Z. Leder, C. Longcope, D. H. Catlin, B. Ahrens, D. A. Schoenfeld, and J. S. Finkelstein Oral Androstenedione Administration and Serum Testosterone Concentrations in Young Men JAMA, February 9, 2000; 283(6): 779 - 782. [Abstract] [Full Text] [PDF]

				S. K. Lim, Y. J. Won, J. H. Lee, S. H. Kwon, E. J. Lee, K. R. Kim, H. C. Lee, K. B. Huh, and B. C. Chung Altered Hydroxylation of Estrogen in Patients with Postmenopausal Osteopenia J. Clin. Endocrinol. Metab., April 1, 1997; 82(4): 1001 - 1006. [Abstract] [Full Text] [PDF]