Low nitric oxide bioavailability is associated with better responses to sildenafil in patients with erectile dysfunction.

Naunyn-Schmiedeberg's archives of pharmacology

PubMedID: 23685845

Muniz JJ, Lacchini R, Sertório JT, Jordão AA, Nobre YT, Tucci S, Martins AC, Tanus-Santos JE. Low nitric oxide bioavailability is associated with better responses to sildenafil in patients with erectile dysfunction. Naunyn Schmiedebergs Arch Pharmacol. 2013;386(9):805-11.
Erectile dysfunction (ED) is a multifactorial disease associated with vascular dysfunction, low nitric oxide (NO) bioavailability, and oxidative stress. However, it is not known whether low NO bioavailability and oxidative stress affect the responsiveness of ED patients to sildenafil. We tested this hypothesis by studying 28 healthy subjects (control group), 26 patients with ED without comorbidities (ED group), and 18 patients with ED and diabetes mellitus (ED/DM group). The International Index for Erectile Function (IIEF) questionnaire was used to assess the erectile function of all participants, and their responsiveness to sildenafil was assessed as the percentage of change in the five-item version of IIEF score before and after sildenafil treatment. Levels of whole blood nitrite, antioxidants markers (ferric reducing ability of plasma (FRAP) and reduced glutathione), and oxidative stress markers (thiobarbituric acid reactive substance and protein carbonyl) were determined. We found a negative correlation between whole blood nitrite levels and the responses to sildenafil in both ED groups (P?