Natriuretic factors

Atrial Natriuretic Peptide, a-Atrial natriuretic peptide [85637-73-6] (ANP) (55), also known as atrial natriuretic factor (ANF), brain natriuretic peptide (BNP) (56), and type C natriuretic peptide (CNP) (57) are members of the ANP family (28). These atrial peptides arise from a common 128 amino acid precursor where the active form of ANP is the 28 amino acid peptide at the C terminus. 

Receptors linked to guanylyl cyclase and which catalyze the formation of guanosine triphosphate (GMP) to guanosine-3A -cychc monophosphate (cychc GMP) include those for atrial natriuretic factor (ANF) and endothehal-derived relaxing factor (EDRF), mediating vasodilatation, and nitric oxide [10102 3-9], NO, or a clearly related derivative. 

Atrial Natriuretic Factor. Atrial natriuretic factor (ANF) has natriuretic, vasorelaxant, and diuretic properties (142). It was originally discovered in atrial tissue, from which extracts were made and subsequendy injected systematically. The responses evoked from the atrial extracts estabhshed the heart as an endocrine organ. 

Natriuretic Peptide Diuretics. Atrial natriuretic peptide (ANP), an endogenous diuretic, natriuretic, and vasodilator, is a peptide hormone primarily synthesized and stored by atrial cardiocytes, and secreted by the atria in response to mechanical stretch of the atria. It was discovered in the cmde extracts of atria in 1981 (51). ANP is also known as anaritide [95896-08-5] atrial natriuretic factor [104595-79-1] (ANF) auriculin ... 

ANF Atrial natriuretic factor IGF-I Insulin-like growth factor-I... 

Cyclic GMP is made from GTP by the enzyme gua-nylyl cyclase, which exists in soluble and membrane-bound forms. Each of these isozymes has unique physiologic properties. The atriopeptins, a family of peptides produced in cardiac atrial tissues, cause natriuresis, diuresis, vasodilation, and inhibition of aldosterone secretion. These peptides (eg, atrial natriuretic factor) bind to and activate the membrane-bound form of guanylyl cyclase. This results in an increase of cGMP by as much as 50-fold in some cases, and this is thought to mediate the effects mentioned above. Other evidence links cGMP to vasodilation. A series of compounds, including nitroprusside, nitroglycerin, nitric oxide, sodium nitrite, and sodium azide, all cause smooth muscle re-... 

ANAb Anti-nuclear antibodies ANCA Anti-neutrophil cytoplasmic auto antibodies cANCA Cytoplasmic ANCA pANCA Perinuclear ANCA AND Anaphylactic degranulation ANF Atrial natriuretic factor ANP Atrial natriuretic peptide Anti-I-A, Anti-I-E Antibody against class II MHC molecule encoded by I-A locus, I-E locus, anti-lg Antibody against an immunoglobulin... 

The heart is located underneath the sternum and between the lungs. In most adults, it weighs between 250 and 350 grams (0.55-0.77 lb). Its major role is to provide oxygen-rich blood to all organs and areas of the body. As a secondary function, the heart secretes atrial natriuretic factor (ANF), a hormone that regulates blood pressure and volume status. The inability of the heart to pump enough blood to maintain normal body requirements is known as heart failure. Refer to Chapter 3 for more information on heart failure. 

L17. Lubbesmeyer, H. J., Woodson, L., Traber, L. D., Flynn, J. T., Herndon, D. N., andTraber, D. L., Immunoreactive atrial natriuretic factor is increased in ovine model of endotoxemia. Am. J. Physiol. 254, R567-R571 (1988). 

ML Maack,T., Role of atrial natriuretic factor in volume control. Kidney Int. 49,1732-1737(1996). 

Samson, W. K., Aguila, M. C., Martinovic, J., Antunes-Rodrigues, J., and Norris, M., Hypothalamic action of atrial natriuretic factor to inhibit vasopressin secretion. Peptides 8,449-454 (1987). 

Vandelen, R.L., Arcuri, K.E., and Napier, M.A. (1985) Identification of a receptor for atrial natriuretic factor in rabbit aorta membranes by affinity cross-linking./. Biol. Chem. 260, 10889-10892. 

Atrial natriuretic factor Lysozyme Fibrinogen a-Synuclein... 

In addition to its pump function, the heart is also a secretory organ. Cardiac cells produce two small peptides, the natriuretic factors, which oppose the vasoconstrictive actions of noradrenaline (norepinephrine) from the sympathetic nervous system and of the peptide angiotensin II. By causing vasodilation and natriuresis (increased excretion of sodium in the urine), atrial natriuretic peptide (ANP) secreted from the atria and B-type natriuretic peptide (BNP) secreted by both atria and probably more significantly, from the ventricles, reduce blood pressure. The stimulus to secretion of natriuretic peptides is wall stretch of the chambers of the heart, indicating volume and pressure overload of the vascular system. A third member of the natriuretic peptide family, CNP, is secreted by endothelial cells. 

Physiologists had postulated for a long time about the existence of a sodium excreting hormone to prevent Na overload and consequent deleterious effects of high blood pressure on the heart and vascular system. At least two such natriuretic factors have been described atrial or A-type and brain or B-type natriuretic factors. Structurally, the natriuretic factors are peptides with a cysteine-cysteine disulfide bridge creating a characteristic loop , this is illustrated by Figure 8.8. 

Atrial natriuretic factor (ANF), produced by cells in the atrium of the heart in response to distension, binds the ANF receptor in vascular smooth muscle and in the kidney. The ANF receptor spans the membrane and has guanylate cyclase activity associated wMi the cytoplasmic domain. It causes relaxation of vascular smooth muscle, resulting in vasodilation, and in the kidney it promotes sodium and water excretion. 

ANF Atrial natriuretic factor (also ANP atrial natriuretic peptide)... 

Tanaka IS, Misono KS, Inagami T (1984) Atrial natriuretic factor in rat hypothalamus, atria and plasma determinations by specific radioimmunoassay. Biochem Biophys Res Commun 124 663-668... 

R. W. Lappe, R. L. Wendt (1986). Atrial natriuretic factor. Annu. Rep. Med. Chem. 21 273-281. K. Nakao, Y. Ogawa, S. Suga, H. Imura (1992). Molecular biology and biochemistry of the natriuretic peptide system. II Natriuretic peptides. J. Hypertens. 10 907. 

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