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Biomedical subjects

M Barinaga

Publications and source records attributed to M Barinaga.

279 records · Page 16Linked to original sources
PubMed1982

Introduction of rat growth hormone gene into mouse fibroblasts via a retroviral DNA vector: expression and regulation.

We have introduced the rat growth hormone gene into mouse fibroblasts via a retroviral DNA vector. The ability of the viral DNA to induce foci in the recipient cells was used as a dominant selection marker. Several copies of rat growth hormone DNA were integrated in the mouse cells. The transformed mouse cells expressed rat growth hormone-specific mRNA and secreted mature rat growth hormone. In rat cells, the expression of this gene is regulated by glucocorticoids. We demonstrate that hormone-dependent regulation transfers with the clone and thus appears to be an intrinsic property of the gene or its RNA products.

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PubMedDate not supplied

Transcriptional regulation of growth hormone gene expression by growth hormone-releasing factor.

Production and release of hormones by the pituitary is known to be under complex hormonal control. Prolactin, for example, is both positively and negatively regulated by steroid and thyroid hormones as well as by peptide hormones. Some hypothalamic releasing factors have been shown to regulate both hormone biosynthesis and hormone release. In the case of growth hormone (GH), glucocorticoids and thyroid hormone stimulate its production, at least in part by stimulating transcription of the GH gene, and somatostatin inhibits and growth hormone-releasing factor (GRF) stimulates its release. So far, however, polypeptide hormone regulation of GH biosynthesis has not been demonstrated. Recently a peptide with GH-releasing activity has been characterized from human pancreatic islet tumours. We report here that pure human pancreatic GRF (hpGRF) stimulates transcription of the GH gene, as well as stimulating GH release.

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PubMedDate not supplied

Independent effects of growth hormone releasing factor on growth hormone release and gene transcription.

The synthesis and secretion of growth hormone (GH) by the somatotropic cells of the anterior pituitary is under complex hormonal regulation. The hypothalamic peptides, growth hormone releasing factor (GHRF) and somatostatin, respectively stimulate and block GH release. We have shown that treatment of primary cultures of rat anterior pituitary cells with GHRF stimulates transcription of the GH gene, as well as GH release, and that this reflects the response of pituitary cells in vivo. Gick et al. have shown a stimulation of GH mRNA levels in normal pituitary cells in response to GHRF. Because normal pituitary cells are the physiological target for GHRF and because they exhibit both transcriptional and release responses to the hormone, they provide a valuable system with which to examine the important possibility of a link between hormone synthesis and release in secretory cells. Using this system, we demonstrate here that GHRF stimulates GH gene transcription independently of GH release and, conversely, that other agents can stimulate GH release without affecting transcription of the GH gene.

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