Research Area: Cardiovascular Disease Biological Activity: Sildenafil citrate is an agent used to treat erectile dysfunction and pulmonary arterial hypertension (PAH). It acts by inhibiting cGMP specific phosphodiesterase type 5, an enzyme that regulates blood flow in the penis. Sildenafil has been the prime treatment for erectile dysfunction. [1]
Legal Information Sold for research purposes under agreement from Pfizer Inc. Biochem/physiol Actions Sildenafil is a potent, selective inhibitor of cGMP specific phosphodiesterase type 5 (PDE5). Sildenafil is used to treat erectile dysfunction and pulmonary arterial hypertension. NO activates guanylate cyclase, which results in increased levels of cGMP, producing smooth muscle relaxation. Sildenafil enhances the effect of NO by inhibiting PDE5, which is responsible for degradation of cGMP.