Intravesical Infusion of Budesonide Foam Improves Symptoms in a Bladder Pain Syndrome/Interstitial Cystitis Rat Model

Purpose: Since intravesically administered steroid therapy may treat bladder pain syndrome/interstitial cystitis (BPS/IC) with fewer side effects than the current treatment of orally administered steroids, we investigated whether the intravesical infusion of budesonide foam can effectively treat BPS/IC symptoms in a rat model of tranilast-induced BPS/IC. Methods: There were 6 rat treatment groups (n = 8 per group): control + single or daily saline infusion, tranilast + single or daily saline infusion, and tranilast + single or daily budesonide infusion. All groups except for the controls were fed a tranilast supplemented diet for 5 weeks. Budesonide and saline were infused intravesically. After the BPS/IC rat model underwent single infusion treatments, we measured the paw pain threshold using the von Frey test and continuous cystometry was taken. After two weeks of daily intravesical infusions, we measured locomotor activity and serum cortisol levels; harvested bladders underwent histological analysis. Results: Both pain threshold and locomotor activity were significantly lower in the saline-infused groups receiving the tranilast diet, but there were no differences between the budesonide-infused groups and the controls. The interval between bladder contractions was significantly shorter in the tranilast group than the control or tranilast + budesonide infusion groups. The serum cortisol levels did not change. Hematoxylin-Eosin stainings of the bladder showed thickening of the bladder muscle layer and mucosal edema in the tranilast group, while the tranilast + budesonide infusion group showed only mild changes. Conclusion: Intravesical infusion of budesonide effectively treated BPS/IC symptoms in a rat model of BPS/IC.