Study On The Effects And Its Mechanisms Of Electroacupuncturing At Zusanli Points (ST36) On The Postoperative Intra-abdominal Adhesions In Rat

Objective:1. Observe the effect of electroacupuncture (EA) at Zusanli points (ST36) on a rat model of postoperative intra-abdominal adhesions; 2. To investigate the effect of EA on inflammatory mediators releases, angiogenesis of abdominal adhesion tissues and expression of VEGF of microvascular endothelial cell; 3. To find out whether anti-inflammatory and organ protective effects of EA are related to cholinergic anti-inflammatory pathway.Methods:Male Wistar rats were randomly assigned into eight groups (each=8). Sham control group (S group), abdominal adhesions alone (C group), abdominal adhesions +electroacupuncture (EA) at Zusanli points (EA group), no-acupoint control (SEA group), abdominal adhesions +bilateral celiac vagotomy (VA group), abdominal adhesions +vagotomy+EA (VA/EA group), abdominal adhesions +α-bungarotoxin (α-BGT group) and abdominal adhesions +α-BGT+EA (α-BGT/EA group). Animal model of abdominal adhesion was produced by scraping on appendix of cecum, followed by a silicone path fixed on the lateral abdominal wall. Bilateral Zusanli points (ST36) were electroacupunctured with constant voltage (2-3mA,2-100Hz) for 1 hour approximately 30min after the surgery of abdominal adhesion. a-BGT (1μg/kg) were injected into abdominal cavity and bilateral celiac vagotomy were operated in the course of surgery. All the animals were sacrificed in the first day, third day and tenth day after the surgery. Levels of inflammatory mediators (TNF-α, NO and NOS) in tissues were detected and the adhesion degree was evaluated by Chiang scale. Adhesion tissues were taken to observe histopathological changes and quantitate vessel density. The changes of VEGF were detected by immunohistochemistry method.Results:1. All rats in abdominal adhesion group developed obvious intra-abdominal adhesions by Chiang scale, indicating that an animal model of abdominal adhesion was successfully established.; 2. The rats respectively were sacrificed in the first day and the third day. Compared with sham control, the abdominal adhesion resulted in significant elevation of inflammatory mediators (TNF-α, NO and NOS); EA at Zusanli points obviously lowered the elevated levels of inflammatory mediators (TNF-α, NO and NOS); 3. Scores of adhesion, angiogenesis and expression of VEGF of adhesion tissues were significantly decreased in EA group compared with those of adhesion group in the tenth day.4. a-BGT injection or bilateral celiac vagotomy further elevated the increased levels of inflammatory mediators compared with Sham control group, and stimulated the angiogenesis and expression of VEGF of adhesion tissues; 5. EA at Zusanli points following the injection of a-BGT or bilateral celiac vagotomy showed less anti-inflammatory and inhibitive effects on abdominal adhesion.Conclusion:1. We successfully set up a animal model in treatment of abdominal adhesion with electroacupuncture in conscious rats; 2. EA at Zusanli points significantly lowered the elevated levels of inflammatory mediators, and attenuated histopathologic changes of adhesion tissue after abdominal adhesion challenge; 3. The activation of cholinergic anti-inflammatory pathway might be one of the mechanisms of EA at Zusanli points exerting the anti-inflammatory and inhibitive effects on abdominal adhesion.