Histological lesion and testosterone biosynthesis impairment in testes from autoimmune rabbits

The aim of the present report is to study comparatively the biosynthesis of testosterone in normal and autoimmune rabbit testes, with different degrees of histological lesion, by in vitro double tracer incubation experiments. For this purpose (3H)-pregnenolone and (14C)-progesterone were used as precursors in the presence of testicular homogenates from both groups of animals. In the autoimmune animals, an impairment in the biotransformation of the precursors leading to a lesser synthesis of testosterone was demonstrated. An accumulation of dehydroepiandrosterone, 17 alpha-hydroxyprogesterone and androstenedione was frequently found. It was also shown that the metabolic impairment seemed to be produced at an earlier stage than the histological modifications. On the other hand, a correlation between the degree of testicular damage and the intensity of metabolic impairment could not be demonstrated conclusively.