Inhibition of the tonic contraction in the treatment of erectile dysfunction.

Erectile dysfunction (ED) reduces the quality of life. It is estimated that 52% of men have some degree of ED, which is associated with ageing. While it is clear that there are a variety of current treatment options for ED, each of these has drawbacks and contraindications. A better understanding of the physiological mechanisms involved in penile erection will provide new ways to treat ED. This review not only focuses on the vasoconstrictors and vasodilators that control the state of contraction and relaxation of the corpora cavernosa smooth muscle, but also presents a novel Ca(2+)-sensitising pathway that contributes to maintaining the penis in the non-erect state. Studies have shown that inhibition of the RhoA/Rho-kinase signalling pathway induces penile erection. Further understanding of this RhoA/Rho-kinase pathway may provide a novel alternative treatment for ED.