Cellular retinoic-acid-binding-protein and retinol-binding-protein mRNA expression in the cells of the rat seminiferous tubules and their regulation by retinoids

Authors

  • Raffaella FARAONIO,

    1. Dipartimento di Biochimica e Biotecnologie Mediche, II Facoltà di Medicina e Chirurgia, Università degli Studi di Napoli, Italy
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  • Michela GALDIERI,

    1. Istituto di Istologia e Embriologia Generale, Facotà di Medicina e Chirurgia, Università di Roma ‘La Sapienza’, Italy
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  • Vittorio COLANTUONI

    Corresponding author
    1. Dipartimento di Biochimica e Biotecnologie Mediche, II Facoltà di Medicina e Chirurgia, Università degli Studi di Napoli, Italy
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Correspondence to V. Colantuoni, Dipartimento di Biochimica e Biotecnologie Mediche, II Facoltà di Medicina, Università degli Studi di Napoli, Via S. pansini 5, I-80131 Napoli, Italy
Fax:+ 39 81 7463074.

Abstract

The levels of the mRNA corresponding to the intracellular binding proteins for retinoic acid and retinol (CRABP1 and CRBP1, respectively) were studied in primary cultures of somatic and germ cells of the rat seminiferous tubules. We show that the CRABP1 mRNA is expressed in Sertoli and germ cells and a single molecular species of mRNA is detected. CRBP1 mRNA is detected in Sertoli and peritubular cells. The regulation of the expression of both genes by retinoids was studied in Sertoli cells. CRABP1 mRNA levels are not affected by either retinoic acid or retinol, whereas both compounds positively regulate CRBP1 mRNA synthesis in a dose-dependent manner. A fivefold increase in CRBP1 mRNA levels was observed 32–48 h after addition of either agent. These results demonstrate that in Sertoli cells the expression of CRABP1 is not affected by retinoids, similar to the situation observed in vivo and in other in-vitro cultures. CRBP1-gene expression is, instead, induced and the variations in CRBP1-mRNA levels may regulate the intracellular concentrations of retinoids, as a response to changes in the vitamin-A nutritional status.

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