Sacral nerve stimulating on intestinal mucosal immune barrier function of rats with acute complete spinal cord injury

Objective: To study the effects of sacral nerve root stimulation on intestinal mucosal immune barrier function in rat with acute complete spinal cord injury(SCI). Methods: Fifty-six Wistar rats were divided into Sham group(SG n=8), control group(CG 24 、 48、 72 h,n=8), and experimental group(EG 24、 48、 72 h,n=8). In CG and EG, according to Fehlings'method,we transected the spinal cord by the aneurysm clip and implanted electrodes into the third sacral foramina on the right side.We stimulated in intensity 4 V,the frequency of 15 Hz,and the pulse of 210 μs.The stimulation period was 2 hours,with 10 minutes stimulation and 10 minutes rest intermittently,twice a day at 8:00-10:00 am and 6:00-8:00 pm. The intestinal morphology was observed under light microscope and electron microscope. The protein expression levels of A20,NOD2,and CD68 by Western blot . Results: ① SCI caused impaired intestinal epithelial barrier function. The intestinal mucosa appeared different degree of damage in CG group; cell-cell connections between intestinal epithelial cells were destroyed; The escherichia coli and other antigen translocated through the injured epithelial cell , M cells, and the leakage to the lamina propria of intestinal villi, which were improved in EG after stimulation.② The expression of A20 in EG was increased ,which had statistical differences between CG or SG(P＜0.01); the expression ofA20 in CG was decreased, which had statistical differences between SG(P＜0.01).The expression of NOD2 in CG was increased, which had statistical differences between SG(24 h,72 h P＜0.05; 48 h P＜0.01);The expression of NOD2 in EG (48 h ,72 h)was decreased, which had statistical differences between CG(48 h P＜0.01,72 h P＜0.05). The expression of NOD2 in EG had no statistical differences between SG. The expression of CD68 in CG was increased,which had statistical differences between SG or EG(P＜0.01).The expression of CD68 in EG was increased in 24 h and 48 h groups ,which had statistical differences between SG(P＜0.01),but had no statistical differences in 72 h group. Conclusion: Sacral nerve root 3 electrostimulation can rehabilitate the peristalsis of intestine,decrease bacterial amount,reduce inflammatory response, enhance endogenous protection, protect the intestinal mucosal immune barrier function.