Effects of temperature, anesthesia, and infection on urinary bladder pain‐like responses in mice

Abstract

Painful bladder syndrome/interstitial cystitis (PBS/IC) is a condition characterized by chronic bladder pain. Patients suffering from PBS/IC are commonly unresponsive to regular pain treatment and current models of bladder pain in animals do not recapitulate many of the important features. We sought to improve this situation through the use of urinary tract infections (UTI) in mice to model the bladder sensitization seen in human patients. In our new system, following UTI, urinary bladder distension (UBD) was combined with visceromotor response (VMR) measurements to evaluate the pain‐like response to bladder distension. In designing this model we discovered several potentially confounding variables such as body temperature and length of isoflurane anesthesia. We found that UBD‐induced VMRs decrease as body temperature decreases. These data suggest that body temperature must be closely controlled during UBD testing. In addition, we found a significant effect related to the length of time under anesthesia. When mice were tested with anesthesia times under two hours, VMR was reduced with increasing length of anesthesia time. Interestingly, after two hours no significant decrease in VMR was seen with increasing length of anesthesia. After controlling for these variables, preliminary data was gathered on the effect of UTI on VMR. The data suggests a modulation of VMR following UTI. Support provided by APS UGSRF.