These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: The involvement of insulin-like growth factor-I in local control of steroidogenesis and DNA synthesis of Leydig and non-Leydig cells in the rat testicular interstitium.
    Author: Moore A, Morris ID.
    Journal: J Endocrinol; 1993 Jul; 138(1):107-14. PubMed ID: 7531750.
    Abstract:
    Insulin-like growth factor-I (IGF-I) peptide, receptors and binding proteins are present in the rodent testis, which strongly implies that IGF-I has one or more testicular functions. In the present study we provide further information to support the concept that IGF-I is an important local mediator in the testis. High concentrations of IGF-I were measurable in interstitial fluid by radioimmunoassay, and IGF-I-binding proteins (IGFBPs) were readily detectable in interstitial fluid by ligand blotting, the predominant type being IGFBP-2. In vitro, IGF-I bound to testicular interstitial cells which did not have 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) activity and which were resistant to ethane dimethanesulphonate treatment. In vitro, IGF-I receptor-mediated actions increased both steroidogenesis and DNA synthesis. Insulin stimulated DNA synthesis at concentrations appropriate to cross-react with the IGF-I receptor, and this effect was greater in a testicular interstitial Leydig cell-depleted cell population compared with a Leydig cell-enriched cell culture. Furthermore, combinations of epidermal growth factor or transforming growth factor -alpha together with insulin appeared to act synergistically, causing extremely large increases in [3H]thymidine incorporation in the interstitial cells. These results support a paracrine and/or autocrine role for IGF-I in interstitial cell growth and development.
    [Abstract] [Full Text] [Related] [New Search]