Angiogenesis Therapy for the Treatment of Erectile Dysfunction

Abstract

Introduction Over the past 15 years, significant advances have been made in the treatment of erectile dysfunction (ED). The most significant of these advances has been pharmacological treatment of ED with phosphodiesterase type 5 (PDE5) inhibitors. This therapy greatly increased the awareness of ED and has helped stimulate research into the underlying causes of ED. While treatment with PDE5 inhibitors continues to be the current therapy of choice, approximately 40% of men treated with PDE5 inhibitors fail to have significant improvement in erectile function and PDE5 inhibitors do not reverse the vasculopathic processes associated with ED. With this in mind, new therapies must be developed. The treatment with angiogenic growth factors such as vascular endothelial cell growth factor (VEGF) may be one such therapy. Aim This review will focus on defining key terms in the angiogenic process, angiogenic growth factors, and different delivery methods, and summarize results from angiogenic therapies for the treatment of ED. Methods A review of the literature was performed on all angiogenic therapies for the treatment of ED. A brief review on the angiogenic factors was also performed Results Angiogenic therapies for the treatment of ED are possible and promising; however, further investigation is needed to advance clinically. Conclusions Although numerous studies have now employed angiogenic factors for the possible treatment of ED in several animal models, we are still not at the point to begin human investigations. Future studies need to examine proper dosage of the angiogenic agent, route of delivery, time course for delivery, and combination therapies.

Identification of Endothelial Progenitor Cells in the Corpus Cavernosum in Rats

“…New treatment strategies include therapeutic angiogenesis and stem cell/gene therapy for the treatment of erectile dysfunction [14]. Angiogenic factors such as VEGF and bFGF have been tried to restore normal penile vasculature function [14, 15].…”

“…Angiogenic factors such as VEGF and bFGF have been tried to restore normal penile vasculature function [14, 15]. The rationale is that these angiogenic factors could replace or repair damaged endothelial cells.…”

Mechanisms of Penile Erection and Basis for Pharmacological Treatment of Erectile Dysfunction

“…The potential for the use of angiogenic factors to restore erectile function, either without the need for PDE5 inhibitors or by enhancing the effect of this class of agents has attracted great interest (Lysiak et al, 2010). Vascular endothelial growth factor is expressed in both rat and human CC (Burchardt et al, 1999a,b), and the expression is down-regulated in the CC of, e.g., hypercholesterolemic rats and rabbits (Byrne et al, 2001;Xie et al, 2005;Ryu et al, 2006).…”

“…Vascular endothelial growth factor is expressed in both rat and human CC (Burchardt et al, 1999a,b), and the expression is down-regulated in the CC of, e.g., hypercholesterolemic rats and rabbits (Byrne et al, 2001;Xie et al, 2005;Ryu et al, 2006). Numerous studies in several animal models of ED have successfully employed intracavernosal delivery of vascular endothelial growth factor and other angiogenic factors (Lysiak et al, 2010). The observations made suggest an advantageous role for therapeutic angiogenesis in the treatment, if not the prevention, of vasculogenic ED.…”

“…The observations made suggest an advantageous role for therapeutic angiogenesis in the treatment, if not the prevention, of vasculogenic ED. However, human investigations have not yet begun (Lysiak et al, 2010).…”