The Natriuretic Peptide Response to Saline Infusion

The primary objective is to evaluate the overarching hypothesis that obese and black individuals have relatively lower circulating natriuretic peptide levels compared with lean and white individuals. Conventional clinical assays for measurement of circulating natriuretic peptides display substantial overlap, precluding determination of the basis of the relative natriuretic peptide deficiency previously observed in these groups. We will study lean or obese, black or white, healthy adult subjects with intravenous (IV) saline infusion as a stimulus for natriuretic peptide production and release. We will measure circulating levels of natriuretic peptide isoforms using mass spectrometry that allows the specific identification of proBNP 1-108 and its cleavage product BNP 1-32.