Abstract
BACKGROUND: We examine the effects of low energy shock wave (LESW) on bladder and mitochondrial function in a rat model of HCl induced cystitis, and the influence of dynamic bladder filling volume on LESW responses. Dysregulation of mitochondria function may impact the urothelial barrier and contribute to bladder dysfunction in patients with Interstitial cystitis/bladder pain syndrome (IC/BPS). METHODS: Female Sprague-Dawley rats underwent urethral catheterization and intravesical instillation of 0.2 ml of 0.4 N HCl (N = 32) or 0.2 ml saline (N = 8) kept for 90 s. After HCl instillation, the bladder received LESW treatment while filled with 0 ml, 0.2 ml or 0.4 ml saline or no LESW treatment. Continuous cystometry (CMG) was performed on day 8. The bladder was harvested after CMG for histology and Western blotting. RESULTS: HCl provoked bladder overactivity, bladder wall inflammation marked by infiltration of mast cells, increased bax/bcl2 ratio consistent with increased TUNEL staining and increased release of mitochondrial-integrity markers (cleaved caspase 3 and Cytochrome c). LESW treatment suppressed HCl provoked bladder overactivity in association with lower inflammatory reaction, mast cells infiltration, and a lower bax/bcl2 ratio also reflected by reduced TUNEL staining and mitochondrial-integrity markers irrespective of the volume of saline in bladder at the time of LESW. CONCLUSIONS: These findings support that antiinflammatory effect of LESW in chemical cystitis is associated with the reversal of the molecular-cellular perturbations in mitochondrial dependent intrinsic apoptotic pathway.