Objective To study the effect and mechanism of electroaeupuncture at acupoint Guanyuan on expression of brain-derived neurotrophic factor (BDNF) and tropomyosine receptor kinase B (TrkB) in spinal cord and excitability of detrusor of rat with urinary retention after spinal cord injury. Methods The model of urinary retention after spinal cord injury was established by using weight drop method. Eighty female Sprague-Dawley rats were randomly divided into four groups, namely, a normal, a sham, a model and an electroacupuncture (EA) group, with 20 rats in each group. The EA group was given electroacupuncture at aeupoint Guanyuau once a day for 10 days in total, while the other groups was given no treatment. After 10 days, the expression level of BDNF and TrkB in spinal cord of injury site was measured by immunohistochemistry staining, and excitability of detrusor was measured by using the muscle strips in vitro. Results It was revealed that, with regard to the expression level of BDNF and TrkB in spinal cord,the model group exceeded the normal and sham group, the EA group significantly exceeded the other groups ( P < 0. 05 ). With regard to the excitability of detrusor, the model group was significant-ly lower than the normal and sham group. The EA group significantly exceeded the model group ( P < 0.05 ). Conclusion Electroacupuncture at acupoint Guanyuan can raise the expression level of BDNF and TrkB in spinal cord and increase the excitability of detrusor in rats with urinary retention after spinal cord injury.

Objective To study the effect of electro-acupuncture(EA)on bladder detrusor apoptosis in rats with urinary retention after spinal cord injury(SCI),compare the effectiveness of different acupoints and explore possible mechanisms.Methods One hundred female adult Sprague-Dawley rats were randomly divided into 5 groups:a normal group,a sham operation group,a model control group,a Guanyuan acupoint(RN4)EA group and a Shuidao acupoint(ST28)EA group,with 20 rats in each group.A model of urinary retention after SCI was established using the weight drop method.The EA groups were given EA once daily for 10 d.The other groups had no treatment.After 10 d of EA,an electron microscope was used to observe the bladder detrusor ultrastructure,and the terminal deoxynucleotidyl transferase dUTP nick end labeling(TUNEL) method and immunohistochemistry were used to observe any apoptosis in the detrusor smooth muscle cells and the expression of apoptosis-related genes bcl-2 and bax.Results After EA treatment,expansion of the rough endoplasmic reticulum was reduced significantly,and the number of edemic mitochondria was reduced compared with the model control group.In the normal and sham operation groups,little apoptosis was observed,and there was no significant difference between the two groups.Apoptosis indices(AIs)were higher in the model control group than in the normal group.The average AI in the Guanyuan EA group was lower than that in the Shuidao group.In the Guanyuan group,bax protein expression was less than that in the Shuidao group and the model group.In the Guanyuan group,bcl-2 protein expression was not significantly different from that in the Shuidao group and the model control group.Conclusion EA at the Guanyuan or Shuidao aeupoint can restrain bladder detrusor apoptosis in rats with urinary retention after SCI.EA may improve the ultrastructure of the detrosor urinae, reduce the expression of bax, change the ratio of bcl-2 to bax, and thus decrease apoptosis.The effect of EA at the Guanyuan acupoint is superior to that at the Shuidao acupoint.