030 Light-controlled relaxation of rat penile corpus cavernosum by a novel NO donor, NO-Rosa

Abstract

Phosphodiesterase-5 inhibitors are not always effective for patients with erectile dysfunction (ED) who also have diabetes mellitus or have had a radical prostatectomy, because of the reduction in nitric oxide (NO) production. The control of NO production may be useful as a therapy for ED. In this study, we focused on a light-controllable NO releaser. Previously, we developed a blue (470–500 nm) light-controllable NO releaser, NOBL-1. Subsequently, we improved NOBL-1, because blue light has low tissue permeability. We have now succeeded in the development of a yellow-green (530–590 nm) light-controllable NO releaser, NO-Rosa. We investigated whether we could control the relaxation of the corpus cavernosum smooth muscle by using an NO-Rosa derivative and light irradiation. Fluorescence imaging of the NO release from NO-Rosa in HEK-293 cells was performed using DAF-FM. Adult male Wistar-ST rats were used for the isometric tension study. The corpus cavernosum was treated by the addition of L-NAME (100 μM) to inhibit endogenous NO production and pre-contracted with noradrenaline (10 μM). The response of the corpus cavernosum smooth muscle to irradiation with yellow-green light, before and after the addition of an NO-Rosa derivative (10 μM), was measured and recorded.