A peptide hormone; increases cAMP concentration in rat platelets (ED50 = 50 nM); decreases mean blood pressure in anesthetized rats at 1 nmol/kg, i.v.; reduces vascular hyperpermeability and increases survival in a rat model of α-toxin-induced septic shock; inhibits binding of human adrenomedullin to rat astrocytes in vitro (IC50 = 0.27 nM)