Developmental pattern of Δ5 3β-hydroxysteroid dehydrogenase activity in isolated rat Leydig cells

Gedalia F. Paz, Jeremy S.D. Winter, Francisco I. Reyes, Charles Faiman*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


A direct method for determination of Δ5 3β-hydroxysteroid dehydrogenase (3β-HSD) activity was employed in isolated Leydig cells (LC) derived from rats on fetal day 19 (F19) and postnatal (N) days 1,12,24, 34 and 45 and adults. The activity of 3β-HSD in the adult LC was 1.15 ± 0.02 (μmole/μg DNA/hr, mean ± SEM, n = 73). Activities in the other groups, expressed as a percentage of the respective adult control, were: F19-38%; N1-39%; N12-8%; N24-89%; N34-166%; and N45-118%. A good correlation was found between histochemical staining for 3β-HSD and the quantitive method employed. Using (3H)-DHA as a substrate, LC isolated from F19, n1 and N12 produced testosterone in appreciable amounts (41%, 55% and 20% of the toal products respectively) whereas at advanced stages of development (N24 to adulthood) the major product was androstenedione (93 ± 1%). These findings may be explained by the observed decrease in 17β-hydroxysteroid dehydrogenase (17β-HSD) activity, due to an insufficient supply of NADPH, in the older vs. earlier stages of development. This study indicates the presence of steroidogenic enzymatic activity in LC throughout development in the rat. It also provides a relatively simple in vitro model for studies of testicular regulation during development.

Original languageEnglish
Pages (from-to)661-674
Number of pages14
Issue number6
StatePublished - Dec 1980
Externally publishedYes


  • 17-dione
  • 17-dione 5α-Androstanedione (5α-A)
  • 17β-diol Testosterone (T)
  • 17β-hydroxy-4-androsten-3-one
  • 3β-hydroxy-5-androsten-17-one
  • 5 α-androstane-3
  • 5α-androstane-3α
  • Androstanediol (A-diol)
  • Androstenedione (A)
  • Dehydroepiandrosterone (DHA)
  • androst-4-ene-3


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