title: Phosphodiesterase-5 inhibition: the molecular biology of erectile function and dysfunction.
abstract: This article discusses the role of phosphodiesterase-5 (PDE-5) inhibition in the molecular biology of erectile function and dysfunction. Commercially marketed PDE-5 inhibitors are highly specific for PDE-5, and in the face of continuing cyclic GMP (cGMP) synthesis,elevate cellular cGMP. This elevation results from direct competitive inhibition of PDE-5 and from blocking the negative feedback regulation of the enzyme. Elevation of cGMP activates cGMP-dependent protein kinase, which mediates the effects of the cGMP-signaling pathway to decrease smooth muscle tone and dilate penile vascular smooth muscle. By exploiting features of PDE-5 regulatory mechanisms that modulate PDE-5 function, the inhibitors enhance their own potencies.
authors.affiliation: Department of Molecular Physiology and Biophysics, Light Hall, Room 702, Vanderbilt University School of Medicine, Nashville, TN 37232-0615, USA. sharron.francis@vanderbilt.edu
authors.forename: Sharron H
authors.initials: SH
authors.lastname: Francis
authors.forename: Jackie D
authors.initials: JD
authors.lastname: Corbin
mesh_terms: D015106:3',5'-Cyclic-GMP Phosphodiesterases; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5; D007172:Erectile Dysfunction / Q000503:physiopathology*; D006801:Humans; D008297:Male; D010410:Penile Erection / Q000187:drug effects / Q000502:physiology*; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology*; D010727:Phosphoric Diester Hydrolases; D015398:Signal Transduction
chemical_list: D010726:Phosphodiesterase Inhibitors; D010727:Phosphoric Diester Hydrolases; D015106:3',5'-Cyclic-GMP Phosphodiesterases; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5; C517381:PDE5A protein, human