Testosterone Secretion by the Early Fetal Pig Testes in Organ Culture

Abstract

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 (P4.0 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.