Objectives: To evaluate the protective effects of inosine on bladder dysfunction, nerve density, and oxidative damage after partial bladder outlet obstruction in rats.
Methods: A total of 60 adult male Sprague-Dawley rats were divided into 5 groups. Groups 1-4 underwent bladder outlet obstruction. Groups 1-3 were treated with inosine at 100, 150, or 225 mg/kg/d intraperitoneally and group 4 with saline. Group 5 consisted of sham-operated control rats. At 21 days postoperatively, cystometry were performed in 30 rats (6 per group). In the remaining 30 rats (6 per group), the bladders were excised and used for contractile responses to various stimulations, immunohistochemical examination for protein gene product 9.5 (a neuronal marker) and evaluation of superoxide dismutase activity and thiobarbituric acid reductase substance level.
Results: Inosine administration resulted in dose-dependent protective effects on the contractile responses to both field stimulation and carbachol, although the protective responses to KCl was restricted to a greater dose of inosine. A dose-dependent reduction in residual volume was noted in inosine-treated groups at different dosages compared with the saline-treated group. In addition, the protein gene product 9.5-positive nerve density decreased in the saline-treated group but significantly increased in the inosine-treated (225 mg/kg/d) group. Compared with the saline-treated group, significantly enhanced superoxide dismutase activity and a reduced thiobarbituric acid reductase substance level were observed in the inosine-treated group at 150 and 225 mg/kg/d.
Conclusions: These results suggest that inosine has a potential protective effect against partial bladder outlet obstruction-induced bladder dysfunction and oxidative injury in rats.