[In vitro studies of testicular biosynthesis in 4 cases of male pseudohermaphrodism (MPH) due to testicular 17 ketoreductase defect (author's transl)].

In 3 cases of MPH due to 17-ketosteroid reductase defect, the pattern of testicular biosynthesis studied after incubating homogenates of testicular tissue with 14C-Progesterone and 3H-Pregnenolone was very similar. The most striking finding was the excessive production of delta 4-Androstenedione contrasting with the small amount of testosterone formed. Conversion of DHA to delta 5-Androstenediol was also limited. In addition, 3 pairs of substrates, namely 14C-testosterone and 3H-delta 4-androstenedione; 14C-estradiol and 3H-estrone; 14C-delta 5-androstenediol and 3H-DHA, were incubated for various length of time. Homogenates of testicular tissue from 2 cases presenting with the biosynthetic defect were studied as to compare to testicular tissues from 2 subjects with normal testicular biosynthesis. Different degrees in the impairment of the reduction or the oxydation were observed for the different pairs of substrates in pathological as well as in normal tissues. This suggests that the extent of the enzyme defect would differ for the 3 pairs of substrates.