Developmental changes in levels of luteinizing hormone receptor and androgen receptor in rat Leydig cells

Endocrinology. 1992 Sep;131(3):1107-14. doi: 10.1210/endo.131.3.1505454.


To further assess the hormonal response capabilities of Leydig cell progenitors (PLC) from 21-day-old rats, their levels of LH and androgen receptors (LH-R and AR) were measured and compared to those of isolated immature (ILC) and adult Leydig cells (ALC) from 35- and 90-day-old rats, respectively. Levels of LH receptor were estimated by Scatchard analysis of binding to [125I]hCG, and levels of LH receptor mRNA were determined by Northern blot analysis using a rat LH receptor antisense RNA probe. The numbers of LH receptors per cell measured by the binding study were 2,623 +/- 1,110 in PLC, 9,024 +/- 1,992 in ILC, and 39,896 +/- 15,234 in ALC (mean +/- SEM of four replicate experiments; ALC significantly greater than either PLC or ILC at P less than 0.05). The Northern blotting revealed three major bands [6.7, 2.6, and 2.3 kilobases (kb)] that were present in Leydig cells at all three ages and were not detected in HepG2 cells. When the steady state levels of the predominant 6.7-kb species were normalized to actin mRNA, PLC were 6.3-fold lower than ILC and 1.7-fold lower than ALC (n = 3 replicate isolations of poly(A) RNA). The 2.6- and 2.3-kb species exhibited similar trends. Levels of AR were estimated by immunoblotting using a polyclonal antibody against a synthetic peptide of the receptor (residues 14-32) that detected a 110-kilodalton AR protein. Levels of AR mRNA were estimated by Northern blot analysis, using a rat AR antisense RNA probe that detected a single 10-kb AR mRNA. The relative levels of AR protein were 1.0, 1.5, and 0.5 in PLC, ILC, and ALC, respectively (n = 3). Similar trends were observed for AR mRNA (n = 3). The observation that both LH and AR levels were lower in PLC compared to ILC is consistent with the hypothesis that the former are progenitors of Leydig cells.

MeSH terms

  • 3-Hydroxysteroid Dehydrogenases / metabolism
  • Actins / genetics
  • Aging / metabolism*
  • Animals
  • Blotting, Northern
  • Cell Line
  • Cells, Cultured
  • Chorionic Gonadotropin / metabolism
  • Humans
  • Kinetics
  • Leydig Cells / metabolism*
  • Male
  • RNA, Messenger / genetics
  • RNA, Messenger / isolation & purification
  • RNA, Messenger / metabolism
  • Rats
  • Rats, Inbred Strains
  • Receptors, Androgen / genetics
  • Receptors, Androgen / isolation & purification
  • Receptors, Androgen / metabolism*
  • Receptors, LH / genetics
  • Receptors, LH / isolation & purification
  • Receptors, LH / metabolism*


  • Actins
  • Chorionic Gonadotropin
  • RNA, Messenger
  • Receptors, Androgen
  • Receptors, LH
  • 3-Hydroxysteroid Dehydrogenases