ABSTRACT
<p><b>OBJECTIVE</b>To investigate the effect of electrical stimulation to sacral spinal nerve 3 (S₃ stimulation) on gastrointestinal dysfunction after spinal cord injury (SCI).</p><p><b>METHODS</b>Six rabbits were taken as normal controls to record their gastrointestinal multipoint biological discharge, colon pressure and rectoanal inhibitory reflex. Electrodes were implanted into S₃ in another 18 rabbits. Then the model of SCI was conducted following Fehling's method: the rabbit S₃ was clamped to induce transverse injury, which was claimed by both somatosensory evoked potential and motion evoked potential. Two hours after SCI, S₃ stimulation was conducted. The 18 rabbits were subdivided into 3 groups to respectively record their gastrointestinal electric activities (n=6), colon pressure (n=6), and rectum pressure (n=6). Firstly the wave frequency was fixed at 15 Hz and pulse width at 400 μs and three stimulus intensities (6 V, 8 V, 10 V) were tested. Then the voltage was fixed at 6 V and the pulse width changed from 200 μs, 400 μs to 600 μs. The response was recorded and analyzed. The condition of defecation was also investigated.</p><p><b>RESULTS</b>After SCI, the mainly demonstrated change was dyskinesia of the single haustrum and distal colon. The rectoanal inhibitory reflex almost disappeared. S₃ stimulation partly recovered the intestinal movement after denervation, promoting defecation. The proper stimulus parameters were 15 Hz, 400 μs, 6 V, 10 s with 20 s intervals and 10 min with 10 min intervals, total 2 h.</p><p><b>CONCLUSION</b>S₃ stimulation is able to restore the intestinal movement after denervation (especially single haustrum and distal colon), which promotes defecation.</p>
Subject(s)
Animals , Rabbits , Disease Models, Animal , Electric Stimulation , Electrodes, Implanted , Evoked Potentials, Motor , Physiology , Evoked Potentials, Somatosensory , Physiology , Gastrointestinal Tract , Sacrum , Spinal Cord InjuriesABSTRACT
Objective To investigate the effect of electrical stimulation of S_3 nerve root on improvement of intestinal mucosal barrier function in rabbits with acute complete spinal cord injury. Methods Model of paraplegia was built by injuring spinal cord in rabbits. Then, the rabbits with electrical stimulation of S_3 nerve root were set as experimental group and those without set as control group. Normal rabbits were set as normal group. Under aseptic condition, portal vein blood was collected for quantitative determination of endotoxin and bacterial culture ; and liver, spleen and mesenteric lymph nodes were collected for bacterial culture and strain identification. Liver, spleen, mesenteric lymph nodes and small intestines were collected from experimental group and control group for pathological HE staining; while small intestine were observed by light and electron microscopes. Results In control group, the intestinal mueosal barrier and the other organs were destroyed obviously, with higher level of Serum endotoxin and higher rate intestinal flora translocation than that in experimental group and normal group. In the experimental group, the electrical stimulation of S_3 nerve root could improve motility of the denervated intestine, with more defecation content, less destruction of the intestinal mucosa and lighter other organ damage compared with control group, serum endotoxin level was significantly reduced compared with control group but showed no statistical difference compared with normal group, with obvious decrease of bacterial translocation rate. Conclusions After spinal cord injury in rabbits, electrical stimulation of S_3 nerve root can facilitate intestinal tract motility, improve intestinal mucosal barrier function and hence alleviate endotoxemia and intestinal bacterial translocation, as is beneficial to reducing SIRS and MOBS.
ABSTRACT
Objective To investigate the intestinal pathophysiological mechanism of bacterial translocation and endotoxemia in rabbits with acute spinal cord injury (SCI). Methods Paraplegia was induced by injuring the spinal cord of 30 rabbits by the method of Fehlings. Twelve rabbits were used for recording the changes of gastrointestinal (GI) electrophysiology and colon pressure. The left 18 rabbits were experimental group and were killed in 24, 48 and 72 h after injury. The other 6 rabbits served as normal group. Under aseptic condition, samples of blood and mesenteric lymph node were collected for bacterial cultures and endotoxin detection. The small intestines were observed by light and electron microscopy. The colons were inspected by light microscopy. Results After SCI, the electrophysiology of the GI tract was changed especially at the middle and distal colon. The peristalsis of the middle and distal colon was reduced and sometimes even disappeared. In the early stage, the main pathology was hyperemia of blood vessel and infiltration of inflammatory cells. The interepithelial tight junctions became wider and the columnar epithelium was disintegrated. All of the pathological changes may lead to the destruction of the intestinal barrier. The endotoxin level were increased since 24 h after SCI and had statistically significant difference compared with that at 72 h (P0.05). Conclusion After SCI, the middle and distal colon dysfunction induces constipation, bacterial overgrowth, and blood flow congestion. These factors may accelerate the destruction of the intestinal barrier and lead to bacterial translocation and endotoxemia.