Bacterial cystitis is accompanied by increased peripheral thermal sensitivity in mice.

PURPOSE: Visceral inflammation and pain associated with chemical cystitis produce increased sensitivity to noxious stimuli in the sacral dermatomes. We determined whether a similar sensitization occurs in response to bacterial cystitis.
MATERIALS AND METHODS: Bacterial cystitis was induced by intravesical instillation of Escherichia coli 1677 in female C57BL/6N and C3H/OuJ mice (Jackson Laboratories, Bar Harbor, Maine). C3H/HeJ mice (Jackson Laboratories) served as a control because C3H/HeJ mice lack functional toll-like receptor 4, which is an essential component of cellular recognition of bacterial lipopolysaccharide. Hind paw sensitivity to thermal stimulus was quantitatively determined 1, 2, 7 and 14 days after infection.
RESULTS: Intravesical instillation of E. coli produced infection in all strains of mice. Infection persisted in all C3H/OuJ and C3H/HeJ mice but it spontaneously cleared in some C57BL/6N mice. Increased sensitivity to thermal stimuli was observed in C57BL/6N and C3H/OuJ mice starting 1 to 2 days after E. coli instillation and it was still present 14 days after instillation. Increased sensitivity to thermal stimuli did not occur in C3H/HeJ mice.
CONCLUSIONS: E. coli induced cystitis produced increased sensitivity to peripheral thermal stimuli in mice with competent toll-like receptor 4.