The Effects of Acupuncture on Bladder Interstitial Cells of Cajal Excitability in Rats with Overactive Bladder

It is well known that acupuncture treatment has an effect on patients with an overactive bladder, but the mechanism of its action remains to be clarified. This study was aimed to investigate the effects of acupuncture on bladder overactivity, and the excitability of interstitial cells of Cajal of the bladder in a rat model of partial bladder outlet obstruction. Electroacupuncture (continuous wave, 30 Hz, 1 mA) was applied to stimulate the Ciliao point (BL32) and the Huiyang point (BL35) of rats for 20 min, 3 days. Results showed that acupuncture suppressed detrusor unstable contraction frequency and decreased detrusor maximum pressure in the bladder filling period. Compared with the normal control rats, HCN2 mRNA and protein expression within the bladder were upregulated and were reversed by electroacupuncture in overactive bladder rats as determined by RT-PCR, western blotting and immunohistochemistry. Moreover, in-vitro cell-cultured OAB rats bladder interstitial cells of Cajal intracellular Ca(2+) concentration were higher than normal control rats, which were lowered after acupuncture treatment. These findings suggest that acupuncture stimulation can suppress bladder overactivity, and regulate the excitability of bladder interstitial cells of Cajal in treatment of overactive bladder myogenic mechanism.