RESUMO
BACKGROUND: To investigate the role of sympathetic nervous system (SNS) in moxibustion-induced immunomodulation, the effects of chemical sympathectomy on moxibustion-induced changes in splenic NK cell cytotoxicity, T and B cell proliferation were studied in Sprague-Dawley male rats. METHODS: Chemical sympathectomy was achieved with intraperitoneal injection of 6-hydroxydopamine 50 mg/kg/day for 3 successive days. Direct moxibustion (6-minute interval, 9 moxa ball, each of which weighing 0.007 g and burning for 40 seconds) was applied on unilateral anterior tibial muscle region where Zusanli (ST36) acupoint is located, once a day for 7 successive days. NK cell cytotoxicity was measured by 4hr-51Cr release assay. Mitogen-induced lymphocyte proliferation was analyzed by [3H]-thymidine incorporation assay. RESULTS: NK cell cytotoxicity was suppressed by moxibustion, more in sympathectomized rats than in vehicle-treated rats. T cell proliferation induced by concanavalin A was not affected by moxibustion. B cell proliferation induced by lipopolysaccharide showed no significant change in vehicle- treated rats, but an increase in sympathectomized rats by moxibustion. Sympathectomy alone induced augmentation of NK cell cytotoxicity and suppression of T cell proliferation. CONCLUSION: These results suggest that SNS has no direct relation with moxibution-induced immunomodulation but has an important role in the mechanism to keep the homeostasis of immune system by tonically inhibiting excessive changes of various immune components.