The submicrosomal distribution in rat and boar testis of some enzymes involved in androgen and 16-androstene biosynthesis.

The submicrosomal localization of enzymes involved in androgen and 16-androstene biosynthesis in rat and boar testis tissue has been studied. 16-androstene production was not evident in the rat testis but two enzymes concerned with androgen generation (17 alpha-hydroxy C21 steroid C-17,20 lyase; 17 beta-hydroxysteroid dehydrogenase, were found predominantly in agranular microsomes. In the boar testis the C-17,10 lyase had a similar distribution to the rat enzyme but the 17 beta-hydroxysteroid dehydrogenase was found to be evenly distributed between the two microsomal types. The enzyme system, "andien-betha synthetase", involved in the conversion of pregnenolone to 5,16-androstadien-3 beta-ol, was found mainly (66%) in the agranular microsomes but had a lower specific activity than those of the two enzymes of androgen biosynthesis that have been studied.