MCUF-651 is an orally active guanylyl cyclase A receptor (GC-A) positive allosteric modulator (PAM) (K D : 397 nM ). MCUF-651 binds to GC-A and selectively enhances the binding of atrial natriuretic peptide (ANP) to GC-A. MCUF-651 enhances ANP-mediated cGMP generation in human cardiac, renal, and fat cells. MCUF-651 inhibits cardiomyocyte hypertrophy.