Testosterone and Erectile Function: A Review of Evidence from Basic Research

Abstract

Androgens are essential for male physical activity and normal erectile function. Hence, age-related testosterone deiciency, known as late-onset hypogonadism (LOH), is considered a risk factor for erectile dysfunction (ED). This chapter summarizes relevant basic research reports examining the efects of testosterone on erectile function. Testosterone afects several organs and is especially active on the erectile tissue. The mechanism of testosterone deiciency efects on erectile function and the results of testosterone replacement therapy (TRT) have been well studied. Testosterone afects nitric oxide (NO) production and phosphodiesterase type 5 (PDE-5) expression in the corpus cavernosum through molecular pathways, preserves smooth muscle contractility by regulating both contraction and relaxation, and maintains the structure of the corpus cavernosum. Interestingly, testosterone deiciency has relationship to neurological diseases, which leads to ED. Testosterone replacement therapy is widely used to treat patients with tes-tosterone deiciency; however, this treatment might also induce some problems. Basic research suggests that PDE-5 inhibitors, L-citrulline, and/or resveratrol therapy might be efective therapeutic options for testosterone deiciency-induced ED. Future research should conirm these indings through more speciic experiments using molecular tools and may shed more light on endocrine-related ED and its possible treatments.