NATRIURETIC HORMONES

Natriuretic peptides act as endocrine and paracrine hormones to regulate extracellular fluid volume and blood pressure at all levels of the circulation. Atrial and brain natriuretic peptides, circulating hormones secreted in response to increased stretch within the cardiac atrium and ventricle, respectively, induce comparable natriuresis, vasodepression, and inhibition of aldosterone via the guanylate-cyclase receptor, NPR-A. C-type natriuretic peptide acts via a different gyanylate-cyclase receptor, NPR-B, to affect vascular cell growth and remodeling. Possible complex interactions among all three natriuretic peptides are reviewed. Although the importance of natriuretic peptides is still being assessed, data from animal studies strongly support an important role for these hormones in cardiovascular homeostasis.