New Unstable Bladder Model in Hypercholesterolemia Rats

Abstract

Objectives To evaluate the voiding function of the new vasculogenic erectile dysfunction (ED) model in hypercholesterolemic rats.

Methods We used 14 adult 12-week-old male Sprague-Dawley rats. The cholesterol group received a 1% cholesterol diet for 8 weeks. During the initial 2 weeks, they also drank water containing 3 mg/mL of NG-nitro-l-arginine methyl ester. After 8 weeks, we performed cystometrography, a detrusor strip contraction study, and pathologic examination of the detrusor to confirm voiding dysfunction. The results of the cholesterol and control groups were compared.

Results Compared with the control group values, the mean serum cholesterol and body weight were significantly elevated in the cholesterol group. The cholesterol group had shorter voiding intervals (377.6 ± 205.4 versus 121.8 ± 79.6 seconds, P <0.01) and a smaller functional bladder volume (1.4 ± 0.7 versus 0.7 ± 0.3 mL, P <0.05) on cystometrography compared with the control group. In the detrusor strip study, the cholesterol group had greater tension in spontaneous activities and an increase (13.1% ± 5.6% versus 28.4% ± 16.2%, P <0.05) in the proportion of purinergic components.

Conclusions This vasculogenic ED rat model showed significantly frequent voiding on cystometrography. Considering the many epidemiologic and experimental data, in addition to the data from this model, ED and overactive bladder could share similar pathophysiologic features or be two symptoms of a systemic disorder. This rat model should be useful in evaluating the mechanism of ED and overactive bladder.