Brain Natriuretic Peptide Administered to Man: Actions and Metabolism*

To investigate the effects and metabolism of brain natriuretic peptide (BNP) in man, eight normal subjects received 3-h infusions of synthetic porcine BNP (2 pmol/kg.min) in a placebo-controlled study. The MCR and plasma half-life of BNP were 2.69 L/min and 3.1 min, respectively. BNP clearly suppressed PRA to less than 50% of placebo values (P less than 0.001). Plasma aldosterone concentrations were also significantly reduced by 30% (P less than 0.05). Urinary sodium excretion tended to rise (P = 0.054), and urinary cGMP excretion was clearly enhanced (P less than 0.01). Systemic and renal hemodynamics, hematocrit, plasma protein concentrations, plasma ACTH, arginine vasopressin, PRL, and catecholamines were unchanged. Porcine BNP has a similar range of effects and is similarly metabolized in man as human ANP. Further elucidation of the possible role of BNP as a circulating hormone in man awaits measurement of tissue and plasma concentrations of human BNP in health and disease and provision of fuller dose-response data for human as well as porcine BNP.