Somatostatin - Coimbatore B. Srikant

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Résumé :
Thirty years have passed since somatostatin was discovered and its hormonal function defined [1,2]. The wide range of anatomical distribution and actions of somatostatin and its receptors stimulated intense scientific and clinical interest, and fostered extensive research into all aspects of its biology including regulation of its gene expression, processing of its precursor, biological and cellular actions relating to regulation cell secretion, motility and proliferation. The development of metabolically stable peptide analogs helped define its usefulness in the treatment of endocrine diseases and cancer. The heterogeneity of somatostatin receptors recognized in 1981 [3] was later shown to result from the existence and variable expression of five distinct subtypes that constitutes two distinct subfamilies with distinguishing pharmacological characteristics [4,5]. The molecular cloning of these receptor subtypes reignited the interest in this field leading to a major increase in our insight into the biology of somatostatin and its receptor subtypes, and has led to the design and development of subtype-selective peptide and non-peptide agonists and antagonists. Significant progress has been made in both basic and clinical research on somatostatin. Noteworthy developments include the role of somatostatin in neuronal patterning, delineation of subtype-selective cytostatic / cytotoxic antiproliferative actions, manipulation of cellular signaling by oligomeric association of somatostatin receptor subtypes amongst themselves or with other G protein-coupled receptors, application of radionuclide-tagged derivatives to localize somatostatin receptor positive tumors and their treatment through targeted delivery of radionuclide or chemotoxin tagged agonists through receptor-mediated endocytosis.

Sommaire:
Somatostatin Gene Structure and Regulation.- Processing and Intracellular Targeting of Somatostatin.- Cortistatin- A Novel Member of the Somatostatin Gene Family.- Molecular Evolution of Somatostatin Genes.- Altered Patterns of Growth Hormone Secretion in Somatostatin Knockout Mice.- Somatostatin Receptor Gene Family - Subtype Selectivity for Ligand Binding.- Expression of Somatostatin Receptors in Human Tissues in Health and Disease.- Coexpression of Multiple Somatostatin Receptors in Individual Cells.- Somatostatin Receptor Subtype Selectivity for Cytotoxic and Cytostatic Signaling.- Somatostatin Receptor Signaling via Protein Tyrosine Phosphatases.- Expression and Function of Somatostatin and its Receptors in Immune Cells.- Physiology of Somatostatin Receptors: From Genetics to Molecular Analysis.- Somatostatin Receptor Imaging.- Somatostatin Analogs in the Treatment of Pituitary Tumors.- Somatostatin Receptor Targeted-Radio-Ablation of Tumors.- Somatostatin Analogue Therapy of Neuro-Endocrine Gastro-Entero Pancreatic Tumors.- Vascular Effects of Somatostatin.- The Use of Somatostatin Analogues in Diabetic Retinopathy.- Somatostatin and its Receptors: Past, Present and the Future.