Testicular Steroid Metabolism In Vitro in an XX-Male

XX-males are known to display dysgenetic gonads with failing sperm production. Since defective male gametogenesis has in certain instances been proposed to be related to an aberrant intratesticular steroid biosynthesis (Steinberger et al. 1974), we have analysed the metabolism of [³H] progesterone in vitro in an XX-male.
The 33-year-old patient was sterile and demonstrated high levels of gonadotrophic hormones in the peripheral circulation, though he displayed ordinary male secondary sex characteristics. Testicular biopsy specimens were incubated with [³H] progesterone. This radiolabelled precursor was found to be avidly metabolized along the so-called "Δ⁴-pathway" towards biologically active C₁₉-androgens in this XX-male, as in testicular tissue derived from adult control subjects.
Furthermore, the relative metabolism of [³H] progesterone per mg of testicular tissue incubated, was observed to be significantly higher in the dysgenetic gonadal tissue derived from the present XX-male as compared to the metabolism in the control subjects.
The amount of [³H] 17α-hydroxyprogesterone synthesized in the XX-male was very high, and also the ratio of [³H] 20α-dihydroprogesterone:[³H]-17α-hydroxyprogesterone was found to be remarkably small, i. e. a pattern repeatedly observed in other hypergonadotrophic individuals (Kjessler & Berg 1976b).
The present investigation thus demonstrated that intratesticular steroidogenesis along the Δ⁴-pathway in vitro may be excellent in dysgenetic gonadal tissue with an XX-chromosomal constitution.