[Distribution of radioactivity in subcellular fractions of genital tract tissue and skeletal muscles of guinea pig embryos after administration of 1 alpha,2 alpha-3H(n) testosterone in vitro].

The dynamics of radioactivity in subcellular fractions of the reproductive system and muscle has been studied in the guinea pig embryos from the 21st day of development till birth after the preincubation in a medium containing 1 alpha,2 alpha-3H(n) testosterone (T-3H). The total uptake of T-3H per mg tissue is higher in the reproductive system than in the muscle and attains the highest values during the period of differentiation of target organs by the male type (30-33 days). The nucleocytoplasmic ratio of radioactivity is shifted towards its increase in the nucleus with maximum on the 41st-45th days and by the moment of birth. Radioactivity in the microsomal fraction is higher than in the cytosol (soluble proteins). From the 27th day of development on, when the hormone uptake becomes selective, the radioactivity in the cytosol from the reproductive organs is higher than in the muscle tissue. The data obtained suggest the importance of processes in microsomes for differentiation and organogenesis of reproductive system.