The inhibitory effect of sacral dorsal root ganglion stimulation on nociceptive and nonnociceptive bladder reflexes in cats.

PURPOSE

To investigate the inhibitory effects of electrical stimulation of sacral dorsal root ganglion (DRG) on bladder activity under non-nociceptive and nociceptive bladder conditions in cats.

MATERIALS AND METHODS

12 cats were divided into non-nociceptive and nociceptive groups. Saline was used to distend the bladder and induce non-nociceptive bladder activity, while acetic acid (AA, 0.25%) was used to induce nociceptive bladder overactivity, S1 or S2 DRG stimulation was applied via a pair of hook electrodes placed in the right S1 and S2 DRG.

RESULTS

In both non-nociceptive and nociceptive groups, stimulation at 3 and 5 Hz significantly increased bladder capacity (BC) and no significantly different between the two frequencies. In non-nociceptive group, S1 DRG stimulation at 3 Hz was as effective (increasing BC to 139.7 ± 5.6 and 166.9 ± 12.21% of control at 1T and 3/2T, respectively) as S2 DRG stimulation (increases BC to 129.2 ± 5.6 and 160.5 ± 13.3% of control). In nociceptive group, AA reduced the BC to 62.6 ± 11.7% of saline control. S1 DRG stimulation at 3 Hz was also as effective (increasing BC to 54.9 ± 5.5 and 61.9 ± 6.0% of saline control at 1T and 3/2T, respectively) as S2 DRG stimulation (increases BC to 58.3 ± 3.7 and 65.6 ± 3.7% of control).

CONCLUSION

This study showed the effective inhibition on bladder activity under both non-nociceptive and nociceptive conditions, suggesting the possibility of sacral DRG stimulation to treat bladder overactivity.