• diabetes mellitus;
  • diet;
  • mice;
  • urinary bladder

Objectives: We investigated the possible changes in lower urinary tract function in mice fed a high fat diet (HFD).

Methods: Male C57BL/6J mice were divided into two different feed groups: normal diet (ND) and HFD (n = 16 in each). The body weight, blood glucose level and voiding frequency/volume (FV) relations (for 24 h) were measured every 4 weeks. At 25 weeks old, blood pressure and heart rate, cystometry and isolated detrusor smooth muscle function were measured. After the experiments, serum fat level was measured.

Results: The body weight and blood glucose level of the HFD group were significantly higher than those of the ND group after 9 weeks old. In the FV measurements, the mean voided volume was not significantly different between the two groups, although voiding frequency, total voided volume and water intake volume in the HFD group were significantly lower than those in the ND group. At 25 weeks old, the mean heart rate in the HFD group was significantly higher than that in the ND group, but no significant difference in the blood pressure was observed. None of the cystometric parameters analyzed showed significant differences between the two groups. The contractile response to either carbachol or high K+ was not significantly different, whereas the contractile response to electrical field stimulation was significantly higher in the HFD group. In the HFD group, the mean total cholesterol level was significantly higher.

Conclusion: The present results suggest that HFD-feeding for 20 weeks in mice unlikely affects bladder function even though it induced diabetes, hyperlipidemia and tachycardia.