Lower urinary tract phenotype of experimental autoimmune cystitis in mouse: a potential animal model for interstitial cystitis

OBJECTIVE

To examine bladder function in a newly developed experimental autoimmune cystitis (EAC) model in female SWXJ strain mice, as a potential animal model for interstitial cystitis (IC).

MATERIALS AND METHODS

In all, 20 SWXJ female mice were divided into two groups: an EAC group immunized with mouse bladder homogenate in complete Freund’s adjuvant (CFA) and a control group immunized with CFA alone. At 4 months after injection, the bladder function of some mice (six) was studied with 24‐h micturition habits using metabolic cages and conscious cystometrography (CMG). The bladder and lung were harvested for histological examination and to assess interferon‐γ (IFN‐γ) mRNA expression.

RESULTS

Histology examination showed obviously thickened lamina propria, infiltration of lymphocytes, giant cells, and increased mast cells in the detrusor muscle of the EAC mice. The lungs of EAC mice showed normal histology. The IFN‐γ mRNA expression increased significantly in the bladder, but not in the lung of the EAC mice. The 24‐h micturition habits measurements showed increased frequency of urination in the EAC mice compared with the controls. Similarly, CMG showed decreased intercontraction intervals and voided volumes per micturition in the EAC mice compared with the controls. However, there were no significant differences in peak voiding pressure or total voiding volume between the EAC and control mice.

CONCLUSIONS

Our murine EAC model has comparable functional and histological alterations to those seen in human IC, and may provide a useful model for the study of the pathogenesis and treatment of IC.