Effect of moxibustion on ATP-sensitive potassium channel (K) of bladder in detrusor overactivity rats.

Objectives: To observe the effect of ginger-salt-partitioned moxibustion on ATP-sensitive potassium (K) channel of bladder in detrusor overactivity (DO) rats.

Methods: Female SD rats were randomly divided into sham operation, model, moxibustion and antagonist groups (=9 in each group). Thorax (T) 10 spinal cord transection was performed by surgery. Ginger-salt partitioned moxibustion was applied to "Shenque" (CV8) for 3 cones, once daily for 14 consecutive days. Rats of the antagonist group were intraperitoneally injected with K channel specific antagonist glibenclamide (10 μg·kg·d) once daily for 14 consecutive days. Urodynamic tests were performed after treatment. The distribution and expression of K channel tetrameric subunit (SUR2B) in the bladder of rats was observed by immunofluorescence. The protein and mRNA expression levels of SUR2B in bladder tissue were detected by Western blot and qPCR respectively.

Results: Compared with the sham operation group, rats of the model group showed intensive and large phasic contractions of the detrusor during bladder filling, the frequency and amplitude of phasic contractions of the detrusor 5 min before leakage were significantly increased (<0.001)；the voiding threshold pressure was significantly decreased (<0.001)；the bladder perfusion volume was increased (<0.001)；the SUR2B protein and mRNA expression in bladder tissue were significantly reduced (<0.001). Compared with the model group and the antagonist group, the above-mentioned indicators in the moxibustion group were all reversed (<0.01, <0.001, <0.05).

Conclusions: Ginger-salt partitioned moxibustion can reduce the frequency and amplitude of detrusor phase contraction during bladder filling and prolong the time of first phase contraction in DO rats, which may be associated with up-regulating the expression level of K channel protein and mRNA, promoting the outflow of potassium ions, and inhibiting the inflow of calcium ions, thus improve the stability of detrusor during storage.