Purpose: Neurogenic erectile dysfunction (ED) is a common side effect of radical prostatectomy (RP) because of cavernous nerve damage. In these patients, the production of nitric oxide (NO), which is important for erection, is decreased in the corpus cavernosum. Therefore, NO donors are useful for post-RP ED. However, short half-life and systemic side effects are problems of NO application in ED therapy. To avert these problems, we developed a red-light controllable NO releaser, NORD-1. This study aimed to investigate the effect of NORD-1 and red-light irradiation on neurogenic ED using a rat model of bilateral cavernous nerve injury (BCNI). Materials and Methods: BCNI and sham operations were conducted on 8-week-old rats. After 4 weeks, erectile function was evaluated using changes in intracavernous pressure (ICP) during electrostimulation of the cavernous nerve. ICP was measured under three conditions; without NORD-1 and red-light irradiation, with NORD-1 and without red-light irradiation, and with NORD-1 and red-light irradiation. SiR650 which absorbs red-light but does not release NO was used for the negative control. After the experiment, localization of NORD-1 was observed using a microscope. Results: Erectile function in a BCNI rat model was significantly decreased compared to sham-operated rats (p<0.05). After injecting NORD-1 into the penis, erectile function did not change without red-light irradiation. However, the combination of NORD-1 and red-light irradiation significantly improved erectile function (p<0.05) without affecting systemic arterial pressure. In contrast, when SiR650 was used, erectile function did not change in all three conditions. NORD-1 was detected only in the corpus cavernosum and not in the urethra and dorsal vein. Conclusions NORD-1 combined with red-light irradiation is effective for ED induced by cavernous nerve injury. This treatment may have low risks of hypotension and urinary incontinence, and it can replace the current treatment for post-RP ED.

Purpose: Patients with diabetes mellitus (DM) often exhibit refractory erectile dysfunction (ED). Red-light-controllable nitric oxide donor (NORD-1) and red-light irradiation have successfully enhanced erectile function in intact rats. In this study, we investigated whether the combination of NORD-1 and red-light irradiation effectively treated ED in streptozotocin (STZ)-treated rats with DM. Materials and Methods: Seven-week-old male Sprague-Dawley rats were used in this study. Rats in the DM and sham groups received intravenous STZ (50 mg/kg) and saline, respectively. One week after treatment, the blood glucose level of rats in the DM group was >250 mg/dL. Five weeks after the treatment, we performed a functional study by measuring intracavernous pressure (ICP) under cavernous nerve stimulation before and after NORD-1 treatment with and without light irradiation. Additionally, we performed an isometric tension study using the corpus cavernosum of rats treated with NORD-1 or the control compound, SiR650. Results: The ICP/mean arterial pressure (MAP) ratio was significantly lower in the DM group than in the sham group before and after NORD-1 treatment without light irradiation (both p<0.05). After NORD-1 treatment with light irradiation, the ICP/MAP ratio in the sham and DM groups was significantly enhanced than before and after NORD-1 treatment without light irradiation (all p<0.05). The ICP/MAP ratio in the DM group after NORD-1 with light irradiation was similar to that in the sham group under normal conditions before NORD-1 treatment. Moreover, the systemic blood pressure was not affected by NORD-1 or light irradiation. In the tension study, the corpus cavernosum of rats treated with SiR650 was not changed by red light in the sham or DM groups. However, the rats treated with NORD-1 were strongly relaxed by red light in both groups. Conclusions NORD-1 and red-light irradiation could improve ED in the presence of DM without lowering blood pressure.

Purpose: Patients with diabetes mellitus (DM) often exhibit refractory erectile dysfunction (ED). Red-light-controllable nitric oxide donor (NORD-1) and red-light irradiation have successfully enhanced erectile function in intact rats. In this study, we investigated whether the combination of NORD-1 and red-light irradiation effectively treated ED in streptozotocin (STZ)-treated rats with DM. Materials and Methods: Seven-week-old male Sprague-Dawley rats were used in this study. Rats in the DM and sham groups received intravenous STZ (50 mg/kg) and saline, respectively. One week after treatment, the blood glucose level of rats in the DM group was >250 mg/dL. Five weeks after the treatment, we performed a functional study by measuring intracavernous pressure (ICP) under cavernous nerve stimulation before and after NORD-1 treatment with and without light irradiation. Additionally, we performed an isometric tension study using the corpus cavernosum of rats treated with NORD-1 or the control compound, SiR650. Results: The ICP/mean arterial pressure (MAP) ratio was significantly lower in the DM group than in the sham group before and after NORD-1 treatment without light irradiation (both p<0.05). After NORD-1 treatment with light irradiation, the ICP/MAP ratio in the sham and DM groups was significantly enhanced than before and after NORD-1 treatment without light irradiation (all p<0.05). The ICP/MAP ratio in the DM group after NORD-1 with light irradiation was similar to that in the sham group under normal conditions before NORD-1 treatment. Moreover, the systemic blood pressure was not affected by NORD-1 or light irradiation. In the tension study, the corpus cavernosum of rats treated with SiR650 was not changed by red light in the sham or DM groups. However, the rats treated with NORD-1 were strongly relaxed by red light in both groups. Conclusions NORD-1 and red-light irradiation could improve ED in the presence of DM without lowering blood pressure.

Purpose: Patients with diabetes mellitus (DM) often exhibit refractory erectile dysfunction (ED). Red-light-controllable nitric oxide donor (NORD-1) and red-light irradiation have successfully enhanced erectile function in intact rats. In this study, we investigated whether the combination of NORD-1 and red-light irradiation effectively treated ED in streptozotocin (STZ)-treated rats with DM. Materials and Methods: Seven-week-old male Sprague-Dawley rats were used in this study. Rats in the DM and sham groups received intravenous STZ (50 mg/kg) and saline, respectively. One week after treatment, the blood glucose level of rats in the DM group was >250 mg/dL. Five weeks after the treatment, we performed a functional study by measuring intracavernous pressure (ICP) under cavernous nerve stimulation before and after NORD-1 treatment with and without light irradiation. Additionally, we performed an isometric tension study using the corpus cavernosum of rats treated with NORD-1 or the control compound, SiR650. Results: The ICP/mean arterial pressure (MAP) ratio was significantly lower in the DM group than in the sham group before and after NORD-1 treatment without light irradiation (both p<0.05). After NORD-1 treatment with light irradiation, the ICP/MAP ratio in the sham and DM groups was significantly enhanced than before and after NORD-1 treatment without light irradiation (all p<0.05). The ICP/MAP ratio in the DM group after NORD-1 with light irradiation was similar to that in the sham group under normal conditions before NORD-1 treatment. Moreover, the systemic blood pressure was not affected by NORD-1 or light irradiation. In the tension study, the corpus cavernosum of rats treated with SiR650 was not changed by red light in the sham or DM groups. However, the rats treated with NORD-1 were strongly relaxed by red light in both groups. Conclusions NORD-1 and red-light irradiation could improve ED in the presence of DM without lowering blood pressure.

Purpose: Patients with diabetes mellitus (DM) often exhibit refractory erectile dysfunction (ED). Red-light-controllable nitric oxide donor (NORD-1) and red-light irradiation have successfully enhanced erectile function in intact rats. In this study, we investigated whether the combination of NORD-1 and red-light irradiation effectively treated ED in streptozotocin (STZ)-treated rats with DM. Materials and Methods: Seven-week-old male Sprague-Dawley rats were used in this study. Rats in the DM and sham groups received intravenous STZ (50 mg/kg) and saline, respectively. One week after treatment, the blood glucose level of rats in the DM group was >250 mg/dL. Five weeks after the treatment, we performed a functional study by measuring intracavernous pressure (ICP) under cavernous nerve stimulation before and after NORD-1 treatment with and without light irradiation. Additionally, we performed an isometric tension study using the corpus cavernosum of rats treated with NORD-1 or the control compound, SiR650. Results: The ICP/mean arterial pressure (MAP) ratio was significantly lower in the DM group than in the sham group before and after NORD-1 treatment without light irradiation (both p<0.05). After NORD-1 treatment with light irradiation, the ICP/MAP ratio in the sham and DM groups was significantly enhanced than before and after NORD-1 treatment without light irradiation (all p<0.05). The ICP/MAP ratio in the DM group after NORD-1 with light irradiation was similar to that in the sham group under normal conditions before NORD-1 treatment. Moreover, the systemic blood pressure was not affected by NORD-1 or light irradiation. In the tension study, the corpus cavernosum of rats treated with SiR650 was not changed by red light in the sham or DM groups. However, the rats treated with NORD-1 were strongly relaxed by red light in both groups. Conclusions NORD-1 and red-light irradiation could improve ED in the presence of DM without lowering blood pressure.

Purpose: Patients with diabetes mellitus (DM) often exhibit refractory erectile dysfunction (ED). Red-light-controllable nitric oxide donor (NORD-1) and red-light irradiation have successfully enhanced erectile function in intact rats. In this study, we investigated whether the combination of NORD-1 and red-light irradiation effectively treated ED in streptozotocin (STZ)-treated rats with DM. Materials and Methods: Seven-week-old male Sprague-Dawley rats were used in this study. Rats in the DM and sham groups received intravenous STZ (50 mg/kg) and saline, respectively. One week after treatment, the blood glucose level of rats in the DM group was >250 mg/dL. Five weeks after the treatment, we performed a functional study by measuring intracavernous pressure (ICP) under cavernous nerve stimulation before and after NORD-1 treatment with and without light irradiation. Additionally, we performed an isometric tension study using the corpus cavernosum of rats treated with NORD-1 or the control compound, SiR650. Results: The ICP/mean arterial pressure (MAP) ratio was significantly lower in the DM group than in the sham group before and after NORD-1 treatment without light irradiation (both p<0.05). After NORD-1 treatment with light irradiation, the ICP/MAP ratio in the sham and DM groups was significantly enhanced than before and after NORD-1 treatment without light irradiation (all p<0.05). The ICP/MAP ratio in the DM group after NORD-1 with light irradiation was similar to that in the sham group under normal conditions before NORD-1 treatment. Moreover, the systemic blood pressure was not affected by NORD-1 or light irradiation. In the tension study, the corpus cavernosum of rats treated with SiR650 was not changed by red light in the sham or DM groups. However, the rats treated with NORD-1 were strongly relaxed by red light in both groups. Conclusions NORD-1 and red-light irradiation could improve ED in the presence of DM without lowering blood pressure.