Steroid 5α-reductase 1 promotes 5α-androstane-3α,17β-diol synthesis in immature mouse testes by two pathways

@article{Mahendroo2004Steroid51,
  title={Steroid 5$\alpha$-reductase 1 promotes 5$\alpha$-androstane-3$\alpha$,17$\beta$-diol synthesis in immature mouse testes by two pathways},
  author={Mala Mahendroo and Jean D. Wilson and James A. Richardson and Richard J. Auchus},
  journal={Molecular and Cellular Endocrinology},
  year={2004},
  volume={222},
  pages={113-120}
}

Ontogeny and pathway of formation of 5α-androstane-3α,17β-diol in the testes of the immature brushtail possum Trichosurus vulpecula

TLDR
The timing of androstanediol formation in the possum testis resembles the process in rodents rather than in the tammar wallaby and that any androStanediol in the circulation probably acts in target tissues via conversion to dihydrotestosterone.

Androgen biosynthetic pathways in the human prostate.

Formation of 5alpha-reduced androgens in the testes and urogenital tract of the grey short-tailed opossum, Monodelphis domestica.

TLDR
It is concluded that the timing of 5alpha-reductase expression in the testes of the grey short-tailed possum resembles that of rodents and the brushtail possum rather than that of the tammar wallaby and that dihydrotestosterone is probably the intracellular androgen responsible for virilisation of the urogenital tract in this species.

Role of the alternate pathway of dihydrotestosterone formation in virilization of the Wolffian ducts of the tammar wallaby, Macropus eugenii.

TLDR
It is concluded that dihydrotestosterone, largely formed in the tissue by the oxidation of androstanediol derived from the testes and also the 5alpha-reduction of testosterone, is responsible for Wolffian duct virilization in this species.

Clinical implications of androgen synthesis via 5alpha-reduced precursors.

TLDR
An alternate pathway to DHT was elucidated in the tammar wallaby pouch young, and studies in knockout mice showed that this pathway uses 5alpha-reductase type 1 to convert 17-hydroxyprogesterone to 5 alpha-reduced androgen precursors.

The backdoor pathway to dihydrotestosterone

  • R. Auchus
  • Biology
    Trends in Endocrinology & Metabolism
  • 2004

Impaired 17,20-Lyase Activity in Male Mice Lacking Cytochrome b5 in Leydig Cells

TLDR
It is concluded that Leydig cell b5 is required for maximal androgen synthesis and to prevent 17-hydroxyprogesterone accumulation in the mouse testis; however, the b5-independent 17,20-lyase activity of mouse steroid 17-Hydroxylase/17,20,lyase is sufficient for normal male genital development and fertility.

Increased activation of the alternative "backdoor" pathway in patients with 21-hydroxylase deficiency: evidence from urinary steroid hormone analysis.

TLDR
The elevated ratios of pdiol to the Δ4 and Δ5 pathway metabolites as well as the higher androsterone to etiocholanolone ratio in patients with 21-OHD indicate postnatal activity of the backdoor pathway with maximum activity during early infancy.
...

References

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5α-androstane-3α, 17β-diol is formed in tammar wallaby pouch young testes by a pathway involving 5α-pregnane-3α, 17α-diol-20-one as a key intermediate

TLDR
It is concluded that expression of steroid 5 α-reductase in the developing wallaby testes allows formation of 5α-reduced androgens by a pathway that involves the formation of testosterone and dihydrotestosterone as intermediates.

Prostate formation in a marsupial is mediated by the testicular androgen 5α-androstane-3α,17β-diol

TLDR
It is shown that the 3α-reduced derivative of DHT, 5α-androstane-3α,17β-diol (5α-adiol), is formed in testes of tammar wallaby pouch young and is higher in male than in female plasma in this species during early sexual differentiation, suggesting that circulating 5α -adiol is a key hormone in male development.

5α-Reductase Isoenzymes 1 and 2 in the Rat Testis During Postnatal Development1

TLDR
It is concluded that both 5αR1 and 5 αR2 isoenzymes are involved in the peak of 5α-reduced androgen biosynthesis in the testis during the pubertal initiation of spermatogenesis.

Progesterone metabolism in vitro by rabbit testes at different stages of development.

TLDR
The formation of significant quantities of 5alpha-reduced C19-steroids, which had been demonstrated previously only in prepubertal testes of rats and mice, was present in prepUbertal as well as adult testis of rabbits.

The 17, 20-lyase activity of cytochrome p450c17 from human fetal testis favors the delta5 steroidogenic pathway.

TLDR
The majority of testosterone biosynthesis in the human testis proceeds through the conversion of pregnenolone to dehydroepiandrosterone via the delta(5) pathway.

Administration of 5α-Androstane-3α,17β-Diol to Female Tammar Wallaby Pouch Young Causes Development of a Mature Prostate and Male Urethra.

TLDR
Results indicate that prostatic development after d 20 in male pouch young is driven by the testes of the tammar wallaby, and administration of larger doses of 5α-adiol enanthate caused supraphysiological growth of the prostate, development of a male-type urethra, and penile growth.