Abstract: AIM: To study the influence of injection agent of pidotimod on function of the immune-system in normal and immune-depressed mice, and to investigate the mechanisms of the immunomodulating action of pidotimod.METHODS: The expressions of TNF-αand IL-6 in mice spleen was detected by RT-PCR method.The effects of pidotimod on phagocytosis functions of mice peritoneal exudate cells was investigated by neutral red phagocytosis.The lymphocyte proliferations induced by Con A or LPS were detected by MTT method.Adopt the serum haemolysis to measure the production of serum antibody.RESULTS: The normal and immune-depressed mice were treated for 14 days with different dosages of pidotimod by injection.Pidotimod can significantly increase the expressions of TNF-αand IL-6 of spleen, potentiate phagocytosis of the peritoneal exudate cells, potentiate the lymphocyte proliferations ability induced by Con A or LPS.CONCLUSION: Pidotimod can potentiate amelioration normal and immune-depressed mice immunesystem function and increase expressions of TNF-αand IL-6 of spleen.

Key words: pidotimod, immunocompetence, macrophages, cytokines, TNF-α, IL-6