Objective: To observe the effect of electroacupuncture (EA) at "Ciliao" (BL 32) on detrusor hyperreflexia and c-fos expression in the sacral segment of spinal cord in rats with spinal cord injury (SCI).
Methods: Thirty-seven adult female Sprague-Dawley rats were randomized into normal control (n=5), SCI model (n=16) and EA (n=16) groups. EA (20 Hz, 3 mA) was applied to bilateral BL 32 for 2 hours, once daily for 14 days. Intravesical pressure was detected by using a pressure transducer and a bioelectric amplifier. The expression of c-fos gene was detected by immunohistochemistry.
Results: In comparison with normal control group, the maximum intravesical pressure (MIVP) raised significantly in model group (P < 0.05), and the compliance of the bladder decreased remarkably (P < 0.05). While compared with model group, MIVP decreased significantly in SCI rats of EA group after EA intervention (P < 0.05), and the vesical compliance increased obviously (P < 0.05). In comparison with normal control group, the mean optical density (OD) value of c-fos immuno-reaction (IR) positive products increased significantly in the sacral cord after SCI in model group (P < 0.05), while compared with model group, the mean OD value of c-fos IR positive products in EA group declined evidently but still being higher than that of normal control group (P < 0.05), displaying a downregulation of c-fos expression after EA.
Conclusion: Electroacupuncture at "Ciliao" (BL 32) can inhibit the overactivity of bladder in SCI rats and reduce the c-fos expression in the sacral cord, suggesting that the declined C-fibers' activity after EA may be one of its mechanism underlying improving detrusor hyperreflexia in spinal cord injury.