Abstract:

Objective To investigate the therapeutic effect and mechanism of electroacupuncture at acupoint“Zhongji”and“Guanyuan”on detrusor hyperreflexes after sacral spinal cord injury in rats. Methods The neurogenic bladder model of sacrosacral spinal cord injury was established by spinal cord transection. The elec⁃ troacupuncture group received electroacupuncture intervention at acupoint“zhongji”and“guanyuan”（10 Hz/ 50 Hz，intensity 1 mA），and the inhibitor group received capsazepine（2.5 mL，100 nmol/L，30 min）. At the end of the study，urine flow dynamics was performed，and the bladder histomatological changes were stained by HE. The positive expression level of C ⁃Kit and P2X2 receptors in ICC cells was observed by immunofluorescence double ⁃ standard method. mRNA and protein expression levels of TRPV1，C ⁃Kit and P2X2 in rat bladder tissues were detected by Western Blot. Results Compared with those of sham operation group，basal bladder pressure and leakage point pressure of model group increased but maximum bladder volume and compliance decreased（P < 0.01），and protein expressions of TRPV1，C⁃Kit and P2X2 in bladder tissue increased（P < 0.01）. Compared with those of model group，basal bladder pressure and leakage point pressure of electroacupuncture group were decreased； maximum bladder capacity and compliance were increased（P < 0.01），and protein expressions of TRPV1，C⁃Kit and P2X2 in bladder tissue were significantly decreased（P < 0.01）. Conclusion Electroacupuncture at“Zhongji” and“Guanyuan”point can lower the expression of P2X2 receptor on ICC cells，reduce the frequency of smooth muscle contraction and improve bladder function by inhibiting TRPV1 channel.

Key words:

electricacupuncture, suprasacral spinal cord injury, neurogenic bladder, transient receptor potential vanilloid 1, interstitial cells of Cajal, P2X2 , receptor