Hormonal regulation of rat Leydig cell cytochrome P-45017 alpha mRNA levels and characterization of a partial length rat P-45017 alpha cDNA

Biochem Biophys Res Commun. 1988 Jul 15;154(1):151-8. doi: 10.1016/0006-291x(88)90663-8.


We have isolated and characterized a P-45017 alpha cDNA fragment from a rat testis library. The partial length rat P-45017 alpha cDNA (1Kb) has high overall nucleotide and deduced amino acid similarity with human and bovine P-45017 alpha cDNA's and contains the conserved tridecapeptide and heme regions, the termination codon and polyadenylation site. Using this rat testis cDNA probe we measured P-45017 alpha mRNA levels of rat Leydig cells from animals treated with hCG. Temporal studies with a low hCG dose showed an early increase in mRNA levels returning to control values at later times, while a higher desensitizing dose caused a marked reduction in the mRNA (24 h) and a small recovery at 48 h. Fetal rat Leydig cells maintained in the presence of LH treated with estradiol showed a 70% decrease in P-45017 alpha mRNA levels and testosterone production followed closely the changes in P-45017 alpha mRNA. These studies suggest that gonadotropin stimulation and desensitization of P-45017 alpha dependent enzymes in the adult rat testis as well as estradiol induced desensitization in fetal Leydig cells are related to levels P-45017 alpha mRNA.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Chorionic Gonadotropin / pharmacology*
  • DNA / genetics*
  • DNA / isolation & purification
  • Genes / drug effects*
  • Kinetics
  • Leydig Cells / drug effects
  • Leydig Cells / enzymology*
  • Luteinizing Hormone / pharmacology*
  • Male
  • Molecular Sequence Data
  • Nucleic Acid Hybridization
  • RNA, Messenger / drug effects
  • RNA, Messenger / genetics*
  • Rats
  • Reference Values
  • Steroid 17-alpha-Hydroxylase / genetics*
  • Steroid Hydroxylases / genetics*


  • Chorionic Gonadotropin
  • RNA, Messenger
  • Luteinizing Hormone
  • DNA
  • Steroid Hydroxylases
  • Steroid 17-alpha-Hydroxylase

Associated data

  • GENBANK/M21208