Atrial Natriuretic Factor
Mammalian atrial myocytes contain specific granules that store a powerful rapidly acting natriuretic/diuretic factor, which is referred to as the atrial natriuretic factor (ANF). So far, ANF has been found in atrial extracts from rat, rabbit, dog, baboon and man. Injection of partially purified rat ANF into rats results in up to a 50-fold increase in urinary sodium chloride excretion within 10 minutes. The effect of ANF appears to be caused by inhibition of sodium chloride reabsorption in the ascending limb of Henley’s loop or in the medullary collecting duct; although, alterations in intrarenal hemodynamics may also participate. The exact mechanism by which ANF alters renal tubular transport is unknown, but the substance does not appear to inhibit sodium-potassium ATPase. ANF does not act through release of a substance from the brain, does not require the intact nervous system for its action and is active in the isolated kidney. Biochemical studies suggest that ANF consists of one or more peptides with molecular weights of 4,000–6,000 daltons. It is also probable that one or more larger molecular species of ANF exist. Currently, the most reliable method for measuring ANF activity is to inject unknown test substances into anesthetized rats and determine the effect on renal sodium excretion. It is not known whether the atrial natriuretic factor is released into the blood stream, and thus its physiological relevance has not been determined. Elucidating the chemical structure of this powerful endogenous natriuretic substance and understanding its mechanism of action in the kidney may lead to the development of new specific diuretic drugs for treating millions of patients with hypertension and heart failure.
KeywordsHigh Performance Liquid Chromatography Filtration Sodium Chloride Fractionation Trypsin
Unable to display preview. Download preview PDF.
- 3.Trippodo NC, MacPhee AA, Cole FE: Partially purified human and rat atrial natriuretic factor. Hypertension 5 (suppl I):I-81–I-88, 1983.Google Scholar
- 7.Huet M, Benchimol S, Castonguay Y, Cantin M: The chemical nature of human atrial specific granules. In: Roy PE, Harris P (eds), Recent advances in studies on carcTiac structure and metabolism, Volume 8, University Park Press, Baltimore 1975, pp 59–76.Google Scholar
- 11.Cupples WA, Veress AT, de Bold AJ, Sonnenberg H: Effect of cardiac atrial extract on segmental nephron transport in the rat kidney. Fed Proc (40):554, 1981 (Abstract).Google Scholar
- 12.Briggs JP, Steipe B, Schubert G, Schnermann J: Micropuncture studies of the renal effects of atrial natriuretic substance. Pflugers Arch (395):271–276, 1982.Google Scholar
- 13.Kleinert HD, Camargo MJF, Sealey JE, Laragh JH, Maack T: Hemodynamic and natriuretic effects of atrial extract in isolated perfused rat kidney. Physiologist (25):298, 1982 (Abstract).Google Scholar
- 14.Link WT, Pamnani MB, Huot SJ, Haddy FJ: Effect of atrial extract on vascular Na -K pump activity. Physiologist (24):59, 1981 (Abstract).Google Scholar
- 15.Thibault G, Garcia R, Cantin M, Genest J: Atrial natriuretic factor. Characterization and partial purification. Hypertension 5(suppl I):I-75–I-80, 1983.Google Scholar
- 16.Pamnani M, Huot S, Jagusiak M, Link W, Haddy FJ: Effect of atrial extract on hemodynamics in rats. Physiologist (25):330, 1982 (Abstract).Google Scholar
- 18.de Bold AJ, Flynn TG: Cardionatrin I. A potent diuretic and natriuretic peptide isolated from the heart atria. Fed Proc (42):611, 1983.Google Scholar
- 19.Montini J, Bagby GJ, Burns AH, Spitzer J J: Exogenous substrate utilization in Ca -tolerant myocytes from adult rat hearts. Am J Physiol 240 (Heart Circ Physiol 9):H659 - H663, 1981.Google Scholar
- 20.Trippodo NC, MacPhee AA, Cole FE: Natriuretic factor in isolated rat atrial myocytes. J Mol Cell Cardiol 14 (Suppl 1):65, 1982.Google Scholar
- 23.Trippodo NC, MacPhee AA, Blakesley HL, Cole FE: Standardization of biological assay of atrial natriuretic factor (ANF). The ANF unit. Fed Proc (42):475, 1983.Google Scholar