Endothelial antioxidant compound prolonged the endothelial anti-apoptotic effects registered after tadalafil treatment in patients with arterial erectile dysfunction.

Introduction. This study evaluated the effects of a chronic treatment with tadalafil, a specific phosphodiesterase V inhibitor, on endothelial apoptosis through changes in the serum concentration of endothelial microparticles (EMPs). EMPs were arbitrarily chosen as a marker of endothelial apoptosis, and the changes in their concentration were monitored before and after treatment. Additionally, administration of endothelial antioxidant compound (EAC) during the follow-up, after discontinuation of tadalafil, was evaluated to determine whether this treatment improved the potential effects of tadalafil on the endothelium. Materials and methods. Seventy-five patients with arterial erectile dysfunction (ED) were evaluated at baseline and after administration of tadalafil (5 mg once daily for 90 days). The IIEF-5 questionnaire was administered, and penile dynamic Doppler and flow-cytometric (serum concentrations of EMPs) analyses were performed before (T0) and after treatment. Time points after tadalafil discontinuation: T1 = after 1 week; T2 = after three months; T3 = after six months. Three different schemes of follow-up were evaluated: group A = follow-up with EAC administration, after tadalafil discontinuation, for six months; group B = follow-up without other treatment; group C = follow-up with placebo during the follow-up, after tadalafil cessation. The events CD45neg-CD144pos-annexinVpos were defined EMPs. Results. Patients treated with tadalafil showed a significant decrease of serum EMPs 1 week after discontinuing tadalafil (16.4±3.6% vs7.1±3.3%). This effect was maintained for up to three months in the group without other treatment during follow-up and was maintained for up to six months in the group treated with EAC during follow-up. Discussion. Chronic treatment with tadalafil reduces endothelial apoptosis in patients with arterial ED. Further, EAC treatment prolongs and stabilizes the duration of anti-apoptotic effects on the endothelium this is initially promoted by tadalafil treatment.