SACUBITRIL'S ACTIVE METABOLITE, LBQ657 INHIBITS NEPRILYSIN, A NEUTRAL ENDOPEPTIDASE THAT WOULD TYPICALLY CLEAVE NATIURETIC PEPTIDES, WHICH INCLUDES: ATRIAL NATRIURETIC PEPTIDE (ANP), BRAIN NATRIURETIC PEPTIDE (BNP), AND C-TYPE NATRIURETIC PEPTIDE (CNP). ANP AND BNP ARE RELEASED UNDER ATRIAL AND VENTRICLE STRESS, WHICH ACTIVATE DOWNSTREAM RECEPTORS LEADING TO VASODILATION, NATRIURESIS AND DIURESIS. UNDER NORMAL CONDITIONS, NEPRILYSIN BREAKS DOWN OTHER VASODILATING PEPTIDES AND ALSO VASOCONSTRICTORS SUCH AS ANGIOTENSIN I AND II, ENDOTHELIN-1 AND PEPTIDE AMYLOID BETA-PROTEIN. THEREFORE, THE INHIBITION OF NEPRILYSIN LEADS TO REDUCED BREAKDOWN AND INCREASED CONCENTRATION OF ENDOGENOUS NATRIURETIC PEPTIDES IN ADDITION TO INCREASED LEVELS OF VASOCONSTRICTING HORMONES SUCH AS ANGIOTENSIN II. (HOWEVER, WHEN COMBINED WITH VALSARTAN, WOULD RESULT IN BLOCKING OF ANGIOTENSIN II TO ITS RECEPTOR, PREVENTING THE VASOCONSTRICTIVE EFFECTS AND RESULTING IN A DECREASE IN VASCULAR RESISTANCE AND BLOOD PRESSURE.) CARDIOVASCULAR AND RENAL EFFECTS OF SACUBITRIL IS A RESULT OF THE INCREASED LEVELS OF PEPTIDES THAT ARE NORMALLY DEGRADED BY NEPRILYSIN.