A novel approach to treating erectile dysfunction with a light-controlled nitric oxide donor

Abstract

It has long been known that nitric oxide (NO) is involved in the initiation and maintenance of erection. For this reason, NO supplementation has been considered a useful target for the treatment of erectile dysfunction (ED), and many studies have been conducted. However, to date, no compounds have been launched for a variety of reasons. One of the reasons is the systemic adverse reactions. In order to solve this problem, we focused on light-controlled NO donors and investigate their potential application in ED treatment. Light-controlled NO donors have three main characteristics: first, they release NO only at the site of light irradiation, second, they release NO only during the time of light irradiation, and third, the amount of NO released can be controlled according to the light intensity. These features suggest that light-responsive NO donors may be useful for ED therapy. Our group has been working on the development of light-controlled NO donors, and has so far developed the blue light-controlled NO donor "NOBL-1", the yellowish-green light-controlled NO donor "NO-Rosa", and the red light-controlled NO donor "NORD-1". Our recent studies have shown that NORD-1 and red light can enhance the erectile response in rats at the in vivo level. Next, we examined the effects of NORD-1 and red light using a neurogenic ED model, which is believed to be less effective than existing ED drugs. The results showed that red light irradiation after NORD-1 administration enhanced the erectile response and improved ED in the neurogenic ED model. These results suggest that NORD-1, a light-controlled NO donor, and red light can enhance the erectile response in rats and may have potential as an ED drug. Although optimization of the compound is essential, it is expected that a new therapeutic approach called photobiotherapy for ED will be developed in the future.