Biology of Reproduction, Vol 15, 25-28, Copyright © 1976 by Society for the Study of Reproduction

Testosterone Secretion by the Early Fetal Pig Testes in Organ Culture

¹ Department of Biomedical Sciences, University of Guelph, Guelph, Ontario, Canada NIG 2W2

The production and secretion of testosterone by fetal pig testes in vitro was investigated at the stage of sexual differentiation. Single gonads from 76 fetal pigs between 2.0 and 5.2 cm crown-rump (C-R) length were cultivated for 36 h on synthetic TC Medium 199. Steroids were extracted from the media (n = 72) and explants (n = 46) with methylene chloride. Contralateral gonads (n = 58) were extracted without cultivation. Testosterone was isolated by partition chromatography on Celite and measured by a competitive protein-binding radioassay. The earliest stage of fetal development at which testosterone was detected in the gonad (>0.5 ng/gonad, n = 6) was at 2.2-2.3 cm C-R length. Greater quantities of the hormone (P<0.01) were found in the explant (1.6 ± 1.0 ng/gonad, n = 6) and medium (32 ± 21 ng/dish, n = 11) at this stage. High levels were obtained in fetuses between 3.2 and 3.9 cm C-R length; mean values (± S.D.) at the peak for testosterone in the uncultivated testes, the explanted testes and the media were 4.0 ± 1.7 ng (n = 8), 29 ± 3.6 ng (n = 8) and 271 ± 48 ng (n = 4), respectively. In spite of greater testes weight, lesser quantities of testosterone were present in extracts from testes and media for the larger fetuses (>4.0 cm C-R length). It was concluded that the fetal pig testis is capable of secreting testosterone and shows a peak in this activity at the stage of sexual differentiation.

Note:
ACKNOWLEDGMENTS This work was supported by a grant from the Medical Research Council of Canada and by the Ontario Ministry of Agriculture and Food. We thank Dr. N. I. Ison for help in the statistical analyses, and J. M. Schneider Ltd., Kitchener, Ontario for use of facilities in collection of pig fetuses.

This article has been cited by other articles:

				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]