Mercedes Vallejo

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The endocrine cells of the rat pancreatic islets of Langerhans, including insulin-producing beta-cells, turn over every 40-50 days by processes of apoptosis and the proliferation and differentiation of new islet cells (neogenesis) from progenitor epithelial cells located in the pancreatic ducts. However, the administration to rats of islet trophic factors(More)
Members of the C/EBP family of basic-leucine zipper (bZip) transcription factors form heterodimers and bind to the CAAT box and other sequence-related enhancer motifs. Using a 32P-labeled protein probe consisting of the bZip domain of C/EBP beta, we isolated a clone encoding C/EBP-related ATF (C/ATF), a bZip protein that heterodimerizes with C/EBP-like(More)
Expression of the homeodomain transcription factor IDX1/IPF1 has been shown to be restricted to cells in the developing foregut that form the pancreatic primordium. In the adult, IDX1/IPF1 is expressed in the duodenum and pancreatic islets. The IDX1/IPF1 gene is required for pancreatic development, and in the human, heterozygous mutations have been linked(More)
The effect of an atrial natriuretic peptide on the secretion of the neurohypophysial peptides arginine vasopressin (AVP) and oxytocin has been studied in vivo and in vitro. Atriopeptin III was administered intracerebroventricularly to conscious rats and plasma concentrations of AVP and oxytocin were determined both in controls and in rats which had their(More)
Homeodomain transcription factors play an important role in the regulation of pancreatic islet function. In previous studies we determined that aristaless-like homeobox 3 (ALX3) is produced in islet cells, binds to the promoter of the insulin gene and regulates its expression. The purpose of the present study was to investigate the functional role of ALX3(More)
The effects of intracerebroventricular administration of neuropeptide Y (NPY) on central monoamine turnover were studied in rats treated with alpha-methyl-p-tyrosine (alpha-MPT). NPY decreased noradrenaline turnover in the brainstem, hypothalamus, midbrain and hippocampus. Dopamine turnover was decreased in the brainstem and striatum of NPY-treated rats.(More)
Chronic intermittent exposure to psychomotor stimulants induces in the striatum the expression of Fos-related proteins (Fras) that persist after the end of drug treatment. We carried out experiments to determine whether such Fras ("chronic Fras') require dopamine D1-class receptor function for their persistent expression in the striatum. We chronically(More)
The transcription factor CHOP (C/EBP homologous protein 10) is a bZIP protein induced by a variety of stimuli that evoke cellular stress responses and has been shown to arrest cell growth and to promote programmed cell death. CHOP cannot form homodimers but forms stable heterodimers with the C/EBP family of activating transcription factors. Although(More)