Fluid homeostasis vasopressin

Birnbaumer M. The V2 vasopressin receptor mutations and fluid homeostasis (Review). Cardiovasc Res 2001 51 409-15. 

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). 

Figure 50-12 Key elements in water homeostasis. So/id //nes indicate osmotically stimulated pathways, and dashed lines Indicate volume-stimulated pathways.The dotted lines indicate negative feedback pathways. Abbreviations ANfl atrial natriuretic peptide AVP, arginine vasopressin CNS, central nervous system C/- extracellular fluid OPR, oropharyngeal reflex. (From Reeves W,AndreoliT.The posterior pituitary and water metabolism. /n Wj7son JD, Foster DW, eds. Williams textbook of endocrinology, 8tb ed. Philadelpbia WB Sounders Co, 1992 312.)...

The regulation of body fluid and sodium homeostasis requires central nervous system mechanisms to coordinate information regarding body fluid status with the appropriate physiological and behavioral responses. Mechanisms have evolved to ensure that the physiological and behavioral responses to a body deficit are appropriate. For example, during periods of water deprivation, renal mechanisms minimize loss of body water. Secretion of the pituitary hormone, arginine vasopressin (AVP), is increased and acts on... 

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