New generation drugs may hold key to alternative erectile dysfunction treatment

Most commonly used drugs for treatment of erectile dysfunction include Sildenafil, ,Tadalafil,Vardenafil and Avanafil and about 70 percent of men with erectile dysfunction (ED) respond to these drugs. All four medications enhance the effects of nitric oxide a natural chemical your body produces that relaxes muscles in the penis. This increases blood flow and allows the patient to get an erection in response to sexual stimulation.Taking one of these medicines will not automatically produce an erection. Sexual stimulation is needed first to cause the release of nitric oxide from penile nerves of patients. These medications amplify that signal, allowing some men to function normally. Oral erectile dysfunction medications are not aphrodisiacs, will not cause excitement and are not needed in men who get normal erections.

But in special situations like patients with diabetes where there is more likelihood of erectile dysfunction only about 50 percent of patients achieve positive results with available drugs. In order to take care of patients of erectile dysfunction with diabetes, researchers from the Smooth Muscle Research Centre at the Dundalk Institute of Technology, in Dundalk, Ireland, are in process of studying two new drugs that may give positive results in patients with diabetes and other intractable cases of erectile dysfunction ED. The article is published ahead of print in the American Journal of Physiology Cell Physiology.

For a successful erection to occur, the smooth muscle in the erectile tissue (corpus cavernosum) must relax, explained Keith Thornbury, PhD, corresponding author of the study. However, constant erection is prevented because the tissue contracts. The contraction is controlled by negatively charged chloride moving from inside the cells to outside. In a chain reaction, the outward flow of chloride causes calcium to flow into the cells. When calcium enters the smooth muscle cells of the erectile tissue, it contracts, preventing erection.

The research team treated cells from the corpus cavernosum of male rabbits with two different chloride channel blocking drugs. They found that both drugs were able to block the flow of chloride, causing the smooth muscle cells to relax. This is a different pathway to treating ED than sildenafil, which hinders the effects of a blood flow-regulating enzyme. "This suggests that chloride channels play an important role in maintaining detumescence [state of non-erection] in the corpus cavernosum and, therefore, might present a future target for treating erectile dysfunction," the researchers wrote.