Regulation of gonadotropin receptors, gonadotropin responsiveness, and cell multiplication by somatomedin-C and insulin in cultured pig Leydig cells

Journal Article · Sat Nov 01 00:00:00 EST 1986 · J. Cell. Physiol.; (United States)

DOI:https://doi.org/10.1002/jcp.1041290218· OSTI ID:6616250

Bernier, M; Chatelain, P; Mather, J P; Saez, J M

The author have investigated the effects of insulin and somatomedin-C/insulin like growth factor I(Sm-C) in purified porcine Leydig cells in vitro on gonadotrophins (hCG) receptor number, hCG responsiveness (cAMP and testosterone production), and thymidine incorporation into DNA. Leydig cells cultured in a serum-free medium containing transferrin, vitamin E, and insulin (5 ..mu..g/ml) maintained fairly constant both hCG receptors and hCG responsiveness. When they were cultured for 3 days in the same medium without insulin, there was a dramatic decline (more than 80%) in both hCG receptor number and hCG responsiveness. However the cAMP but not the testosterone response to forskolin was normal. Both insulin and Sm-C at nanomolar concentrations prevent the decline of both hCG receptors and hCG-induced cAMP production. At nanomolar concentrations, Sm-C and insulin enhanced hCG-induced testosterone production but the effect of Sm-C was significantly higher than that of insulin. However, the effect of insulin at higher concentrations (5 ..mu..g/ml) was significantly higher than that of Sm-C at 50 ng/ml. In contrast, at nanomolar concentrations only Sm-C stimulated (/sup 3/H)-thymidine incorporation into DNA and cell multiplication, the stimulatory effect of insulin on these parameters, was seen only at micromolar concentrations. These results indicate that both Sm-C and insulin acting through the receptors increase Leydig cell steroidogenic responsiveness to hCG by increasing hCG receptor number and improving some step beyond cAMP formation. In contrast, the mitogenic effects of insulin are mediated only through Sm-C receptors.

• Research Organization: INSERM, Lyon, France
• OSTI ID: 6616250
• Journal Information: J. Cell. Physiol.; (United States), Vol. 129:2
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
GONADOTROPINS
RADIORECEPTOR ASSAY
INSULIN
BIOLOGICAL EFFECTS
SOMATOSTATIN
TESTOSTERONE
RADIOIMMUNOASSAY
IODINE 125
RECEPTORS
SODIUM IODIDES
SWINE
THYMIDINE
TRITIUM COMPOUNDS
ALKALI METAL COMPOUNDS
ANDROGENS
ANDROSTANES
ANIMALS
AZINES
BETA DECAY RADIOISOTOPES
DAYS LIVING RADIOISOTOPES
DOMESTIC ANIMALS
ELECTRON CAPTURE RADIOISOTOPES
HALIDES
HALOGEN COMPOUNDS
HETEROCYCLIC COMPOUNDS
HORMONES
HYDROXY COMPOUNDS
IMMUNOASSAY
IMMUNOLOGY
INORGANIC PHOSPHORS
INTERMEDIATE MASS NUCLEI
IODIDES
IODINE COMPOUNDS
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KETONES
LABELLED COMPOUNDS
MAMMALS
MEMBRANE PROTEINS
NUCLEI
NUCLEOSIDES
NUCLEOTIDES
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PEPTIDE HORMONES
PHOSPHORS
PITUITARY HORMONES
PROTEINS
PYRIMIDINES
RADIOASSAY
RADIOIMMUNOLOGY
RADIOISOTOPES
RIBOSIDES
SODIUM COMPOUNDS
STEROID HORMONES
STEROIDS
TRACER TECHNIQUES
VERTEBRATES
550601* - Medicine- Unsealed Radionuclides in Diagnostics