Route of bacterial translocation in a rat model after spinal cord injury

Abstract:

Objective：To investigate the route of gut bacterial translocation in a rat model after spinal cord injury（SCI）. Methods：Es－cherichia coli labeled with enhance green fluorescent protein was inoculated to track bacterial translocation. ②Twenty-four Wistar rats were divided into normal group（n=8） and injury 24 h group（n=8） and injury 48 h group（n=8）. ③Liver and mesenteric lymph nodes were analyzed with bacterial cultures；the portal vein was analyzed with endotoxin assays；the small intestines were observed un－der light microscope，fluorescence microscope and electron microscope；liver and mesenteric lymph nodes were observed under light microscope. Results：①SCI caused impaired intestinal epithelial barrier function. The escherichia coli translocated through the injured epithelial cell or the leakage to the lamina propria of intestinal villi. ②The lymph nodes were injured. Positive rates：injury 24 h group（100%，8/8），injury 48 h group（100%，8/8）. ③The histologic change of liver was apparent. Positive rates：injury 24 h group （87.5%，7/8），injury 48 h group（100%，8/8）. ④Endotoxin levels in injury 24 h group and injury 48 h group were significantly differ－ent from that of normal group（F=69.774，P=0.000）. Conclusion：After SCI，the intestinal barrier function is damaged and the bacteria and endotoxin are increased. Due to the increased permeability of intestinal mucosal，the bacteria translocate from the gut to other places through lymphatic and blood routes and form the endotoxemia，which amplifies the local and general inflammation and formu－lates a vicious circle.