BIOLOGICAL CHARACTERIZATION OF HUMAN BRAIN NATRIURETIC PEPTIDE (BNP) AND RAT BNP - SPECIES-SPECIFIC ACTIONS OF BNP

We examined the diuretic-natriuretic activities of rat BNP and human BNP in anesthetized rats in vivo and their vasorelaxant activities for rat thoracic aorta and porcine coronary artery in vitro. Rat BNP was almost equipotent to rat ANP in diuresis and natriuresis with relative potencies of 1.6 and 2.5, respectively, while human BNP exerted no significant activity. Rat ANP, rat BNP and human BNP relaxed PGF2α-contracted rat aortic strips with IC50 values of 0.62, 0.64 and 12.1 nM, respectively, while they relaxed PGF2α-contracted porcine coronary arteries with IC50 values of 0.04, 1.10 and 0.02 nM, respectively. These results strongly suggest that the biological action of BNP is species-specific. © 1990 Academic Press, Inc.