“…For instance, interspecies differences of the basal blood level of testosterone in male mice can be determined by different functional activity of the pituitary [4]. On the other hand, injection of the same dose of CG in vivo (50 ng) to male mice of 6 inbreed strains (A/He, CBA/Lac, C57Bl/6J, DD, YT, and PT) stimulated the appearance of interstrain differences by blood level of testosterone [7]. Hence, potentialities of hormonal functions of the testes can be determined by the power of the "steroidogenic machinery" of Leydig cells.…”