This Article Full Text (PDF) Alert me when this article is cited 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 IMPERATO-McGINLEY, J. Articles by VAUGHAN, E. D. Search for Related Content PubMed PubMed Citation Articles by IMPERATO-McGINLEY, J. Articles by VAUGHAN, E. D., JR.

Nipple Differentiation in Fetal Male Rats Treated with an Inhibitor of the Enzyme 5-Reductase: Definition of a Selective Role for Dihydrotestosterone^*

Division of Endocrinology and Metabolism, Department of Medicine, and the Division of Urology,Department of Surgery, Cornell University Medical College New York, New York 10021

Address requests for reprints to: Dr. Julianne Imperato-McGinley,Division of Endocrinology and Metabolism, Cornell University Medical College, 1300 York Avenue, Room A-328, New York, New York 10021.

Abstract

In the rat, androgens are responsible for sexually dimorphic nipple differentiation. Nipples are expressed in the female, while in the male, the nipple anlage regress prenatally. Mammary gland development is present in both sexes. Treatment of pregnant Sprague-Dawley rats from days 12–21 of gestation with the aza-steroid 17β-N,N-düsopropylcarbamoyl-4-aza-5-androstan-3-one, a competitive inhibitor of the enzyme 5-reductase, resulted in nipple development in male offspring. Additionally, there was feminization of the external genitalia, with urethral displacement to the base of the phallus.

The role of androgens in suppression of nipple anlage in the male rat fetus is known. This study, however, suggests for the first time a selective role for 5-dihydrotestosterone in regression of the nipple anlage in utero. Thus, 5-dihydrotestosterone may be critical not only for masculinization of the external genitalia, but also for inhibition of nipple development in the male rat fetus. (Endocrinology 118: 132-137,1986)

Footnotes

^* This work was supported by NIH Grant HD-9421.

Received June 5, 1985.

This article has been cited by other articles:

				N. J. Barlow, B. S. Mcintyre, and P. M.D. Foster Male Reproductive Tract Lesions at 6, 12, and 18 Months of Age Following in Utero Exposure to Di(n-butyl) Phthalate Toxicol Pathol, January 1, 2004; 32(1): 79 - 90. [Abstract] [PDF]

				C. J. Bowman, N. J. Barlow, K. J. Turner, D. G. Wallace, and P. M. D. Foster Effects of in Utero Exposure to Finasteride on Androgen-Dependent Reproductive Development in the Male Rat Toxicol. Sci., August 1, 2003; 74(2): 393 - 406. [Abstract] [Full Text] [PDF]

				P. M.D. Foster and B. S. Mcintyre Endocrine Active Agents: Implications of Adverse and Non-Adverse Changes Toxicol Pathol, January 1, 2002; 30(1): 59 - 65. [Abstract] [PDF]

				B. S. McIntyre, N. J. Barlow, and P. M. D. Foster Androgen-Mediated Development in Male Rat Offspring Exposed to Flutamide in Utero: Permanence and Correlation of Early Postnatal Changes in Anogenital Distance and Nipple Retention with Malformations in Androgen-Dependent Tissues Toxicol. Sci., August 1, 2001; 62(2): 236 - 249. [Abstract] [Full Text] [PDF]

				P. C. White and P. W. Speiser Congenital Adrenal Hyperplasia due to 21-Hydroxylase Deficiency Endocr. Rev., June 1, 2000; 21(3): 245 - 291. [Abstract] [Full Text]

				E. Mylchreest, D. G. Wallace, R. C. Cattley, and P. M. D. Foster Dose-Dependent Alterations in Androgen-Regulated Male Reproductive Development in Rats Exposed to Di(n-butyl) Phthalate during Late Gestation Toxicol. Sci., May 1, 2000; 55(1): 143 - 151. [Abstract] [Full Text] [PDF]