The genetic control of the activities of microsomal steroidogenic enzymes in Leydig cells of inbred strains of mice.

摘要

Activities of 3beta-hydroxysteroid dehydrogenase-isomerase, microsomal cytochrome P-45017beta and 17-ketosteroid reductase were compared in the Leydig cells of 6 inbred strains of mice (A/He, CBA/Lac, C57BL/6J, DD, YT and PT). The activities of theenzymes varied considerably from one strain to another, depending on the genotype. Analysis of testosterone biosynthesis revealed a low activity of 17-ketosteroid reductase compared with that of the other enzymes. Pregnenolone and progesterone metabolismalso differed among the strains due to genotypic differences in the activities of the microsomal steroidogenic enzymes. It is suggested that there may be a major gene affecting the activities of these enzymes.