Biology of Reproduction, Vol 13, 318-321, Copyright © 1975 by Society for the Study of Reproduction

Testosterone Levels in Early Fetal Testes of Domestic Pigs

¹ Department of Biomedical Sciences University of Guelph Guelph, Ontario, Canada

The content and concentration of testosterone in fetal gonads of domestic pigs was investigated for the early stages of pregnancy. Measurements were made with a competitive-protein binding radioassay after column chromatography of the extracts. Gonads were obtained from 283 male fetuses ranging in size from 2.0 to 12.0 cm crown-rump (C-R) length. Testosterone was present in measurable amounts in gonads from the smallest specimens and reached a peak content of >4.0 ng per pair of gonads near the 4.0 cm C-R stage. A decrease in testicular testosterone values was then noted until the 5.1-5.3 cm C-R length and was followed by rising amounts of testosterone as the testes weight increased in the larger fetuses. Testes weight of 240 fetuses from 3.0 to 12.0 cm C-R length showed an almost linear increase over the entire range of fetal sizes. Gonads from 43 individual female fetuses (3.0-7.0 cm C-R length) contained no measurable amounts of testosterone. No testosterone was detectable in extracts of pairs of adrenal glands from 17 male and female fetuses (3.0-6.0 cm C-R length). These data suggest that fetal pig testes alone show a pattern of higher testosterone production at male sexual differentiation.

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				M.A. Kaminski, C.J. Corbin, and A.J. Conley Development and Differentiation of the Interstitial and Tubular Compartments of Fetal Porcine Testes Biol Reprod, January 1, 1999; 60(1): 119 - 127. [Abstract] [Full Text]