Synthesis and biological properties of two dimeric forms of human α-atrial natriuretic peptide

AbstractTwo dimeric forms of human α-atrial natriuretic peptide (α-ANP) were synthesized by solution methods and compared with monomeric α-ANP in terms of some biological and immunochemical properties. The parallel form (β'-ANP) and the antiparallel form (β-ANP) were equipotent in smooth muscle relaxant activity in isolated rat aorta and their ED50 values were estimated to be 1.7 × 10−8 M and 1.6 × 10−8 M, respectively. Diuretic and natriuretic responses induced by β-ANP and β'-ANP in anesthetized rats were equally less potent but exhibited a significantly longer duration than those induced by α-ANP. β-ANP and β'-ANP possessed immunoreactivities of 60–100% and 50–90% (α-ANP, 100% on a molar basis), respectively, with three different antisera raised against α-ANP-related peptides