Abnormal circulating B-type natriuretic peptide concentration Increased circulating brain natriuretic peptide concentration 2021-01-15T12:59:46Z Elevated circulating BNP concentration An increased concentration of brain natriuretic peptide in the blood circulation. Increased B-type natriuretic peptide Increased ventricular natriuretic peptide BNP is a hormone secreted by ventricular cardiomyocytes in response to stretching caused by increased ventricular blood volume. BNP is synthesized as a prohormone (proBNP) comprising 108 amino acids. After the release into the circulation proBNP is cleaved in equimolar amounts into the biologically active BNP (32 amino acid), and the biologically inactive 76 amino acid N-terminal fragment (NT-proBNP). BNP has a number of physiological effects including natriuresis and diuresis, peripheral vasodilation, inhibition of renin angiotensin aldosterone system (RAAS) and the sympathetic nervous system (SNS).