Advertisement

Induction of 3β-Hydroxysteroid Dehydrogenase Activity by Insulin-Like Growth Factor-I in Primary Culture of Purified Leydig Cells

  • T. Lin
  • N. Vinson
  • J. Haskett
  • E. P. Murono
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 219)

Abstract

Recent evidence suggests that insulin-like growth factor-I (IGF-I)/ somatomedin C (Sm C) may be involved in modulating gonadal steroidogenesis. High affinity IGF-I binding sites were found in a membrane fraction of whole testes and crude interstitial cells (Takano et al., 1976; Handelsman et al., 1985). Patients with isolated growth hormone deficiency have delayed puberty and low IGF-I levels (Zapf et al., 1981). Adequate therapy with growth hormone during childhood permits the occurrence of normal spontaneous adolescence (Laron et al., 1983). Recently we have reported that IGF-I has direct stimulatory effects on Leydig cell steroidogenesis (Lin et al., 1986a). hCG-stimulated testosterone was markedly enhanced in the presence of IGF-I. Furthermore, IGF-I also potentiated 8-bromo cyclic AMP-induced testosterone formation and hCG-stimulated cyclic AMP formation. This suggests that IGF-I has effects both at the hCG receptor sites and at the steps beyond cyclic AMP formation. In the present study, we have evaluated the effect of IGF-I on 3β-hydroxysteroid dehydrogenase activity (3β-HSD). 3β-HSD is one of the key enzymes associated with the smooth endoplasmic reticulum (SER) which converts Δ5-3β-hydroxysteroids to Δ4–3-ketosteroids. 3β-HSD activity is localized exclusively in the Leydig cells and its activity appears to be regulated by LH and hCG (Hafiez et al., 1974).

Keywords

Leydig Cell Vary Time Period Isolate Growth Hormone Deficiency Direct Stimulatory Effect Leydig Cell Steroidogenesis 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. D’Ercole AJ, Stiles AD, Underwood LE, 1984. Tissue concentrations of somatomedin C: further evidence for multiple sites of synthesis and paracrine or autocrine mechanism of action. Proc Natl Acad Sci 81:935–939PubMedCrossRefGoogle Scholar
  2. Hafiez AA, Philpott JE, Bartke A, 1971. The role of prolactin in the regulation of testicular function: the effect of prolactin and luteinizing hormone on 3β-hydroxysteroid dehydrogenase activity in the testes of mice and rats. J Endocrinol 50:619–623PubMedCrossRefGoogle Scholar
  3. Handelsman DJ, Spaliviero JA, Scott CD, Baxter RC, 1985. Identification of insulin-like growth factor-I and its receptors in the rat testis. Acta Endocrinol (Copenh) 109:543–549Google Scholar
  4. Laron Z, Minouni F, Pertzelan A, 1983. Effects of human growth hormone therapy on penile and testicular size in boys with isolated growth hormone deficiency: first year of treatment. Isr J Med Sci 19:338–344PubMedGoogle Scholar
  5. Lin T, Haskell J, Vinson N, Terracio L, 1986a. Direct stimulatory effects of insulin-like growth factor-I on Leydig cell steroidogenesis in primary culture. Biochem Biophys Res Commun 137:950–956PubMedCrossRefGoogle Scholar
  6. Lin T, Haskell J, Vinson N, Terracio L, 1986b. Characterization of insulin and insulin-like growth factor-I receptors of purified Leydig cells and their role in steroidogenesis: a comparative study. Endocrinology 119:1641–1647PubMedCrossRefGoogle Scholar
  7. Murono EP, 1983. Ethanol directly inhibits Δ5–3β-hydrosteroid dehydro-genase-isomerase activity of rat testis interstitial cells. Steroids 42:457–468PubMedCrossRefGoogle Scholar
  8. Rechler MM, Nissley SP, 1985. The nature of regulation of the receptors for insulin-like growth factors. Annu Rev Physiol 47:425–442PubMedCrossRefGoogle Scholar
  9. Ruiz de Galarreta CM, Fanjul LF, Meidan R, Hsueh AJW, 1983. Regulation of 3β -hydroxysteroid dehydrogenase activity by human chorionic gonadotropin, androgens and anti-androgens in cultured testicular cells. J Biol Chem 258:10988–10996Google Scholar
  10. Takano K, Hall K, Frylund K, Sievertsson H, 1976. Binding of somatomedins and insulin to plasma membrane prepared from rat and monkey tissue. Horm Metab Res 8:16–24PubMedCrossRefGoogle Scholar
  11. Tres LL, Smith E, Van Wyk JJ, Kierszenbaum AL, 1986. Immunoreactive sites and accumulation of somatomedin C in rat Sertoli-spermatogenic cell co-culture. Exp Cell Res 162:33–50PubMedCrossRefGoogle Scholar
  12. Zapf J, Walter H, Froesch ER, 1981. Radioimmunological determination of insulin-like growth factor I and II in normal subjects and in patients with growth disorders and extrahepatic tumor hypoglycemia. J Clin Invest 68:1321–1330PubMedCrossRefGoogle Scholar
  13. Zangger I, Eberwine J, Barchas JD, Janson M, Rosenfeld RG, Hoffman AR, Hintz RL, 1986. Tissue distribution and abundance of IGF-I mRNA. Clin Res 34:68AGoogle Scholar

Copyright information

© Plenum Press, New York 1987

Authors and Affiliations

  • T. Lin
    • 1
    • 2
  • N. Vinson
    • 1
    • 2
  • J. Haskett
    • 1
    • 2
  • E. P. Murono
    • 1
    • 2
  1. 1.Medical and Research ServiceWJB Dorn Veterans’ HospitalColumbiaUSA
  2. 2.Departments of Medicine, Pharmacology and PhysiologyUniversity of South Carolina School of MedicineColumbiaUSA

Personalised recommendations