A novel rat model for investigating erectile function after nerve-sparing radical prostatectomy.

Abstract

The rehabilitation of erectile function post-radical prostatectomy remains a great challenge in clinical practice. We aimed to develop a novel rat model suitable for investigating erectile dysfunction (ED) following nerve-sparing radical prostatectomy (NSRP) and to validate its applicability. Thirty-two male Sprague-Dawley rats were randomly assigned to undergo either a novel NSRP modeling procedure or sham surgery. The surgical protocol for the NSRP group included identification and dissection of the major pelvic ganglia and cavernous nerve, prostatectomy, and reconstruction of the lower urinary tract. Mean arterial pressure (MAP) and intracavernous pressure (ICP) were assessed at 1 and 2 weeks postoperatively. Subsequently, the penis tissues were collected for histopathological analyses. The results showed that rats in the NSRP group exhibited significantly lower maximum ICP/MAP ratios (0.39 ± 0.17 vs 0.77 ± 0.08, P < 0.0001) and areas under the ICP curve (2090.13 ± 1050.15 vs 4326.08 ± 1042.08, P = 0.0001) compared to the sham-operated group at 1 week postoperatively. By 2 weeks postoperatively, the NSRP group showed a significant improvement in both the maximum ICP/MAP ratio (0.73 ± 0.09 vs 0.39 ± 0.17, P < 0.0001) and the area under the ICP curve (3654.40 ± 679.28 vs 2090.13 ± 1050.15, P = 0.005) compared to the 1-week post-NSRP group. However, the area under the ICP curve in the NSRP group remained significantly lower than that in the sham-operated group at 2 weeks postoperatively (3654.40 ± 679.28 vs 5259.10 ± 951.48, P = 0.003). Similarly, histological staining suggested that smooth muscle atrophy and collagen deposition in the penis gradually improved over time post-NSRP. However, significant differences in the ratio of smooth muscle to collagen remained between the NSRP and sham-operated groups at 2 weeks postoperatively (0.22 ± 0.03 vs 0.27 ± 0.05, P = 0.011). In conclusion, this study established a novel rat model for investigating post-NSRP ED and validated its utility through erectile function monitoring and histological analysis. Further promising preclinical studies using this model are necessary to explore underlying mechanisms and evaluate the efficacy of treatments for post-NSRP ED.