Testosterone production in fetal testes of the silver fox.
Testosterone content was studied in fetal serum and testes of silver foxes during different periods of prenatal life. The first sign of testosterone synthesis in the testes could be detected starting from the 31st day of gestation by radioimmunoassay. Subsequently its content sharply increased and showed maximum value on the 50th day. Detectable serum testosterone level in male silver fox fetus was noted from the 40th day, its serum concentration increased in prenatal life, but only insignificantly. Testicular production of testosterone was stimulated by hCG at the stages studied from Day 40 on. It is supposed that silver fox testes were able to respond to gonadotrophin not earlier than by Day 40 of prenatal life, but the establishment of pituitary-testicular interrelationship was clearly demonstrated at the end of embryogenesis (Day 50).
Osadchuk
L V
LV
Institute of Cytology and Genetics, Siberian Department of the Russian Academy of Sciences, Novosibirsk, 630090, Russia.