Diabetes mellitus induced erectile dysfunction (DMED) is difficult to treat. The oxidative stress (OS) created by DM is a major cause of injuries to the corpus cavernosum (CC), thereby resulting in ED. Near-infrared (NIR) laser has already been shown to be effective in treating multiple brain disorders due to its anti-OS effect.
To investigate whether an NIR laser improves the erectile function of DMED rats through its anti-OS effect.
Knowing its advantage of reasonable deep tissue penetration and good photo activation on mitochondria, a NIR laser with wavelength of 808nm was used in the experiment. Since the internal and external CC was covered by different tissue layers, the laser penetration rates of the internal and external CC were measured separately. Different radiant exposure settings were applied: in the initial experiment, 40 male SD rats were randomly assigned to five groups, normal controls (NC), and STZ-induced DM rats that 10 weeks later received various radiant exposures (J/cm2) from the NIR laser (DM0J, DM1J, DM2J, and DM4J) in the subsequent 2 weeks. Erectile function was then assessed 1 week after NIR treatment. It was found the initial radiant-exposure setting was not optimal according to the Arndt-Schulz rule. We followed with a second experiment using a different radiant exposure setting. Forty male rats were randomly divided into five groups (NC, DM0J, DM4J, DM8J, and DM16J), and the NIR laser was again applied according the new setting and erectile function was assessed as in the first experiment. Histologic, biochemical analyses and proteomic were then conducted.
Recovery of erectile function of varying degrees was observed in the NIR treatment groups, and radiant exposure of 4 J/cm2 achieved optimal results. The NIR4J group showed improvement in mitochondrial function and in morphology in DM rats, and it was found that OS levels were significantly reduced by NIR exposure. The tissue structure of the CC was also improved by NIR exposure. The proteomics analysis confirming multiple biologic processes had been changed by DM and NIR.
NIR laser activated mitochondria, improved OS, repaired the damage to penile CC tissue structures caused by DM, and improved erectile function in DM rats. These results thus raise the possibility that human patients with DMED may respond to NIR therapy in a manner that parallels the responses we observed in animal study. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.