[Effect and mechanism of electroacupuncture for postoperative ileus at perioperative stage]

To observe the intervention effect of electroacupuncture (EA) on small intestinal motility in the rats of postoperative ileus (POI) at perioperative stage and explore the mechanism on the regulation of interstitial cells of Cajal (ICC) in the treatment of POI.

Sixty heathy male SD rats were randomized into a sham-operation group, a model group, an EA group and a sham-EA group, 15 rats in each one. Except the sham-operation group, POI modeling was done in the rest groups. In the EA group, separately, 48 h, 24 h and 0.5 h before modeling, during modeling and 6 h, 12 h and 24 h after modeling, EA was given bilaterally to "Zusanli" (ST 36), 5 Hz, 1-2 mA, for 30 min. The sham-EA stimulation was given in the sham-EA group at the same time points. The same fixation was the only intervention in the model group. No intervention was applied in the sham-operation group. Five rats were selected randomly from each group 6 h, 12 h and 24 h after modeling for the determination of small intestine motility and they were sacrificed. Afterwards, the small intestinal muscular layer was collected for the determination of c-kit and P2X7 mRNA. In 24 h of modeling, the immunofluorescence test was done for c-kit determination.

In 6 h, 12 h and 24 h of modeling, in the model group, the EA groupand the sham-EA group, the small intestine motility was apparently lower than that in the sham-operation group at the same time points (all P<0.01). In 6 h and 12 h of modeling, the small intestine motility in the EA group was not different significantly as compared with that in the model group (both P>0.05). In 24 h of modeling, the small intestine motility in the EA group was better than that in the model group and the sham-EA group at the same time points (both P<0.05). The difference was not significant between the sham-EA group and the model group (P>0.05). In 6 h, 12 h and 24 h of modeling, c-kit mRNA expression of small intestine muscular layer was reduced apparently in the model group (all P<0.01) and P2X7 mRNA expression did not change apparently (all P>0.05). In 24 h of modeling, as compared with the model group and the sham-EA group, c-kit mRNA expression and positive cell area in the small intestine muscular layer were increased in the EA group (all P<0.01).

EA effectively increases the small intestinal motility in POI rats, shortens the recovery time, which is probably closely relevant with the increase of ICC count in small intestinal muscular layer.