Hormone release, inhibitors

Hypothalamic factors. A growth hormone-release inhibitor (somatostatin) has been Isolated from hypothalamic extracts of sheep and its primary structure determined . This tetradecapeptlde can suppress exercise-induced plasma growth hormone rise in normal and diabetic subjects . However, the therapeutic potential of somatostatin in treating diabetic... 

Hormonal therapies that have been studied in the treatment of primary or early breast cancer include antiestrogens, oophorectomy, ovarian irradiation, luteinizing hormone-releasing hormone (LHRH) agonists, and aromatase inhibitors. 

Atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and C-type natriuretic peptide (CNP) are members of a family of so-called natriuretic peptides, synthesized predominantly in the cardiac atrium, ventricle, and vascular endothelial cells, respectively (G13, Y2). ANP is a 28-amino-acid polypeptide hormone released into the circulation in response to atrial stretch (L3). ANP acts (Fig. 8) on the kidney to increase sodium excretion and glomerular filtration rate (GFR), to antagonize renal vasoconstriction, and to inhibit renin secretion (Ml). In the cardiovascular system, ANP antagonizes vasoconstriction and shifts fluid from the intravascular to the interstitial compartment (G14). In the adrenal cortex, ANP is a powerful inhibitor of aldosterone synthesis (E6, N3). At the hypothalamic level, ANP inhibits vasopressin secretion (S3). It has been shown that some of the effects of ANP are mediated via a newly discovered hormone, called adreno-medullin, controlling fluid and electrolyte homeostasis (S8). The diuretic and blood pressure-lowering effect of ANP may be partially due to adrenomedullin (V5). 

Mitsushima D, Hei DL, Terasawa E GABA is an inhibitory neurotransmitter restricting the release of luteinizing hormone-releasing hormone before the onset of puberty. Proc Natl Acad Sci USA 91 395-399, 1994 Miura N, Nakata N, Tanaka Y, et al Improving effects of FG-7080 a serotonin reuptake inhibitor on scopolamine-induced performance deficits of memory tasks in rats. Jpn J Pharmacol 62 203-206, 1993 Mizuta T, Segawa T Chronic effects of imipramine and lithium on 5-HT receptor subtypes in rat frontal cortex, hippocampus and choroid plexus quantitative receptor autoradiographic analysis. Jpn J Pharmacol 50 315-326, 1989... 

Somatostatin is a cyclic tetradecapeptide hormone, characterized as the major physiological inhibitor of growth hormone released from the pituitary, but inhibits the release of many other physiologically important compounds, including insulin, glucagon, gastrin, and secretin (Wolkowitz, 1994). 

Several powerful in vitro biological activities have been described for the products of the AA epoxygenases. The EETs" " have been described as (a) mediators for the release of several peptide hormones, (b) inhibitors of Na reabsorption in the distal nephron, (c) vasodilators in several microvas-cular beds and activators of Ca" -dependent vascular channels, mediators of Ca " influx in several isolated cell systems, powerful mitogens, and mediators of EGF and Angiotensin II signaling. 

Azapeptides are a unique class of pseudopeptides in which a nitrogen atom is substituted for the C H (Fig. 6) [136]. These analogues have been extensively used as enzyme inhibitors (ACE [137], serine protease [138] and hormone analogues [luteinizing hormone-releasing hormone (LHRH) [139], oxytocin, enkephalin] [136]. In the past few years, several groups have in-... 

Thionamides are the most important class of antithyroid compounds in clinical practice used in nondestructive therapy of hyperthyroidism. These agents are potent inhibitors of TPO, which is responsible for the iodination of tyrosine residues of thyroglobulin and the coupling of iodotyrosine residues to form iodothyronines. These drugs have no effect on the iodide pump or on thyroid hormone release. The most clinically useful thionamides are thioureylenes, which are five- or six-membered heterocyclic derivatives of thiourea and include the thiouracil 6-n-propyl-2-thiouracil (PTU) and the thioimidazole 1-methyl-2-mercaptoimidazole (methimazole, Tapazole, MMI). The uptake of these drugs into the thyroid gland is stimulated by TSH and inhibited by iodide. 

Gonadotropin-releasing hormone Growth hormone-releasing hormone Corticotropin-releasing hormone Proiactin inhibitor factor... 

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