The Immune Mechanism In The Regulation Of Gastric Motility By Electroacupuncture: A Laboratory Study

As we all know, not only gastric motility but also immune system can be regulated by acupuncture at zusanli (ST36), one of the most important acupoints of the stomach channel of foot-Yangming. It was found in recent studies that a close relationship exists between immune system and gastric motility, and that the change in immune system can often result in the disorder of gastric motility. Whereas it is not clear what links the two function, and whether the regulatory effects of acupuncture on gastric motility results from those on immune system.In the present study, an animal model of endotoxemia was used, in which disorder of both immune system and gastric motility occurred. Electroacupuncture (EA) was used to investigate whether it has regulatory effects on immune system and gastric motility during endotoxemia. Then, the possible mechanism and the materials involved in the meridian-viscera relationship was discussed.*Supported by the National Natural Science Foundation of China. NO. 399708885METHODS:Lipopolysaccharide (LPS) was administered intraperitoneally to obtain the animal model of endotoxemia. Radioimmunoassay, nitrate reductase method and immunohistochemistry were used to investigate the regulatory effects of EA at zusanli on the plasma concentrations of TNF-cc, IL-lp, IL-6, NO and the number of NOS immunoreactive cells in dorsal motor nucleus of the vagus (DMV) in medulla oblongata of rats. Meanwhile, gastric emptying rate of liquids was measured by phenol red method.RESULTS:1. Plasma concentrations of TNF-a, IL-1 p, IL-6 and NO were significantly higher in rats with endotoxemia than hi normal controls (/*<0.01). The number of NOS immunoreactive cells in DMV increased time-dependently with the LPS treatment. Gastric emptying of liquids was retarded markedly by LPS compared with normal control.2. In the zusanli group, plasma concentrations of TNF-a, IL-lp, IL-6 and NO decreased significantly compared with LPS treatment alone (PO.01; PO.05; PO.01). A down-regulation was also observed in the number of NOS immunoreactive cells in DMV (P<0.01,v.s LPS group). At the same time gastric emptying rate increased significantly (PO.05, vs LPS group).3. In general, no significant difference can be observed between the effects of EA for 5 days and 3 days. But weaker effects were observed in EA for 1 day.4. In comparison with LPS group, no significant change was observed in the non-meridian-non-acupoint group.CONCLUSION:Both the functions of immune system and gastric motility change in rats6with endotoxmia. EA at zusanli has significant regulatory effects on them. DMV also plays a role in it. These results suggest that the immune factors may contribute to the retardness of gastric emptying in endotoxemia, and the regulatory effects of EA at zusanli on gastric motility maybe results from its effects on immunity. It is indicated that immune factors such as cytokines and NO may be the materials which constitute the foundation of the meridian-viscera relationship, and the essence of meridian maybe relate to immunity.