Peptide hormones release

Vasopressin is a peptide hormone released by the posterior pituitary in response to rising plasma tonicity or falling blood... 

Vasopressin is a peptide hormone released by the posterior pituitary in response to rising plasma tonicity or falling blood pressure. Vasopressin possesses antidiuretic and vasopressor properties. A deficiency of this hormone results in diabetes insipidus (see Chapters 15 and 17). 

ACTH adrenocorticoh ophic hormone is a peptide hormone released by anterior pituitary cells in response to shessful stimuli that causes the synthesis and release of cortisol (corticosteroid) from the adrenal cortex. It is an important component of the hypothalamic-pituitary-adrenal (HPA) axis. ACTH is released from pro-opiomelanocortin and secreted from corticotropes in response to corticotropin-releasing hormone (CRH) released by the hypothalamus. 

SRIF acts as an excitatory neuromodulator in the CNS inhibiting the release of TRH, corticotropin-releasing hormone (CRH), growth hormone releasing factor (GHRH), and NE. It produces general arousal and hypotension. It inhibits the release of a number of peptides and modulators in the GI tract. 

J (339), a 28-amino acid peptide, is a member of a family of stmctuially related peptides that includes secretin [1393-25-5] (340), growth hormone releasing factor (GRF), and pituitary adenylate cyclase-activating peptide (PACAP) [137061(341) (83). 

Kinins are a group of peptide hormones of 8-11 residues that act locally as proinflammatory agents, often through the release of powerful downstream effectors such as nitric oxide and/or prostaglandins. 

Somatostatin is a regulatory cyclic peptide, which has originally been described as a hypothalamic growth hormone release-inhibiting factor. It is produced throughout the central nervous system (CNS) as well as in secretoty cells of the periphery and mediates its regulatory functions on cellular processes such as neurotransmission, smooth muscle contraction, secretion and cell proliferation via a family of seven transmembrane domain G-protein-coupled receptors termed sstx 5. 

HPLC High Performance Liquid Chromatography LHRH Lutenizing Hormone Releasing Hormone PTC Phase transfer catalyst SPPS Solid Phase Peptide Synthesis TFA Trifluoro acetic acid... 

Somatostatin. Somatostatin is an endogenous peptide hormone involved in e.g. the control of the release of Somatomedin, Insulin and Pancreatin. Due to its biological role, Somatostatin has a very low biological stability. The half-life in the rabbit after intravenous administration has been determined to approximately 90 seconds in this investigation. After sc or im administration, the apparent half-life is somewhat longer, close to 10 minutes, probably due to the absorption of the peptide from the injection site into the systemic circulation. 

Vasopressin is a peptide hormone produced by the hypothalamus and secreted by the posterior pituitary in response to stimulation. Normal stimuli for vasopressin release are hyperosmolarity and hypovolemia, with thresholds for secretion of greater than 280 mOsm/kg and greater than 20% plasma volume depletion. A number of other stimuli, such as pain, nausea, epinephrine, and numerous drugs, induce release of vasopressin. Vasopressin release is inhibited by volume expansion, ethanol, and norepinephrine. The physiological effect of vasopressin is to promote free water clearence by altering the permeability of the renal collecting duct to water. In addition, it has a direct vasoconstrictor effect. Consequently, vasopressin results in water retention and volume restoration. In patients with septic shock, vasopressin is appropriately secreted in response to hypovolemia and to elevated serum osmolarity (R14). 

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). 

Protein/peptide hormones are derived from amino acids. These hormones are preformed and stored for future use in membrane-bound secretory granules. When needed, they are released by exocytosis. Protein/peptide hormones are water soluble, circulate in the blood predominantly in an unbound form, and thus tend to have short half-lives. Because these hormones are unable to cross the cell membranes of their target tissues, they bind to receptors... 

Atrial natriuretic peptide is released from myocardial cells in the atria of the heart in response to an increase in atrial filling, or an increase in plasma volume. This hormone inhibits the release of renin. With less angiotensin Il-induced vasoconstriction of the afferent arteriole, RBF, GFR, and urine output increase. The increased loss of water and solutes decreases blood volume toward normal. 

Frieboes, R. M., Murck, H., Maier, P. et al. (1995). Growth hormone-releasing peptide-6 stimulates sleep, growth hormone, ACTH and cortisol release in normal man. Neuroendocrinology 61, 584-9. 

Kojima, M Hosoda, H., Date, Y. et al. (1999). Ghrelin is a growth-hormone-releasing acylated peptide from stomach. Nature 402, 656-60. 

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