[Androgen deficiency and erectile dysfunction].

Androgen not only indirectly affects penile erection by enhancing sexual desire and arousal, but also play an important role in maintaining the normal structure of the erectile tissue. Testosterone deficiency may result in a reduction of trabecular smooth muscle content concomitant with increased accumulation of extracellular matrix and deposition of adipocytes in the subtunical region. All this can lead to corporal veno-occlusive dysfunction. In addition, testosterone can affect the expression and activity of nitric oxide synthases (NOS) and RhoA/Rho kinase and influence penile erection directly. Androgen administration may restore erectile function for hypogonadal patients with erectile dysfunction who fail to respond to PDE5 inhibitors alone.