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

Abstract

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. 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. 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. E. coli induced cystitis produced increased sensitivity to peripheral thermal stimuli in mice with competent toll-like receptor 4.