Nitric Oxide in the Penis—Science and Therapeutic Implications from Erectile Dysfunction to Priapism

Perhaps as much as any other subspecialty of urology, sexual medicine has undergone a wondrous evolution in the past 10–20 years. Great advances have been made generating from the study and discovery of molecular mechanisms governing diverse sexual functions. This observation is particularly relevant to the field of erection physiology. Our patients with erectile dysfunction have benefited accordingly as recipients of improved therapies along with optimized management strategies, from which they have gained increasingly healthful and high‐quality lives. Undoubtedly, the developments related to the study of nitric oxide in the biology of the penis have taken center stage amid this progress. Nitric oxide, an evanescent seemingly trivial gaseous chemical, has been quite a force in bringing the sphere of sexual medicine forward. Widely acknowledged at this time is the fact that nitric oxide subserves a fundamental mechanism responsible for the erectile response. This knowledge has been translated into successful pharmacotherapy, as demonstrated by the creation of oral phosphodiesterase type 5 (PDE5) inhibitor therapy (i.e., sildenafil, tadalafil, vardenafil), based on nitric oxide signaling in the penis, for the treatment of erectile dysfunction.