Adrenomedullin and the integrative physiology of fluid and electrolyte balance.

Adrenomedullin (AM) is hypothesized to be a physiologically relevant regulator in fluid and electrolyte homeostasis. AM acts within the central nervous system to inhibit both water and salt intake. The peptide has direct actions in the hypothalamus to decrease vasopressin secretion and in the pituitary gland to inhibit ACTH release. AM decreases production and release of aldosterone from the adrenal glands and acts directly in the kidneys to increase renal blood flow and cause diuresis and natriuresis. Whether or not these complementary actions in brain, pituitary, adrenal gland, and kidney reflect coordinated regulatory mechanisms is currently unknown. Development of molecular tools to determine the physiologic role of endogenous AM will greatly enhance our understanding of AM and its regulation of fluid and electrolyte homeostasis. Copyright 2002 Wiley-Liss, Inc.