Animal model for the study of the relationship between lower urinary tract symptoms/bladder outlet obstruction and erectile dysfunction

Objectives: Lower urinary tract symptoms (LUTS) are frequently associated with erectile dysfunction (ED) in aged men, and both significantly influence quality of life. However, the mechanism linking LUTS to ED has not been clarified completely. The purpose of the present study was to establish an animal model of ED following LUTS/bladder outlet obstruction (BOO) and investigate the expression of molecules related to the cause of this type of ED. Methods: Male Sprague-Dawley rats with partial BOO were used as an experimental model of LUTS. Sham-operated animals served as controls. Voiding and erectile function were evaluated 4, 8, and 16 weeks after obstruction or sham operation. The mRNA expression of penile tissue genes related to penile corporal smooth muscle relaxation was examined by quantitative real-time reverse transcription-polymerase chain reaction. Results: Voiding and bladder function of BOO rats were significantly worse than in sham-operated rats 4, 8, and 16 weeks after obstruction. The erectile function of BOO rats was significantly decreased compared with that of the sham-operated controls (P < 0.01) 16 weeks after obstruction, although it was similar to that of sham-operated animals at 4 and 8 weeks after obstruction. The expression of endothelial nitric oxide synthase (eNOS) mRNA was significantly decreased 16 weeks after obstruction compared with that in sham-operated rats (P < 0.01). Conclusion: An animal model for investigations into the association between LUTS and ED is described herein. Endothelial dysfunction induced by impaired eNOS function is likely to be involved in ED following LUTS/BOO.