Inhibitory effects of nitric oxide and interleukin-10 on production of tumor necrosis factor alpha, interleukin-1 beta, and interleukin-6 in mouse alveolar macrophages

AIM: To observe the effects of nitric oxide and interleukin-10 (IL-10) on i nflammatory reaction in mouse alveolar macrophages ( AM). METHODS: AM from mice were stimulated by lipopolysaccharides (LPS) 10 mg . L-1 and nitric-ox ide synthase inhibitor, S-methylisothiorea sulfate (SMT) or nitric-oxide do nor, S-nitroso-N-acetyl-D, L-penicillamine ( SNAP). The production of tumor necrosis factor alpha (TNF alpha), IL-1 beta, IL-6, and IL-10 by AM were m easured by ELISA. RESULTS: After LPS-stimulation, TNF alpha, IL-1 beta, and IL-6 peaked at 6, 12, and 24 h, respectively by AM. SMT inhibited LPS-indu ced nitric oxide release and increased IL-1 beta and IL-6 secretions in AM, but the TNF alpha levels remained unchanged. SNAP had inhibitory effects o n IL-1 beta and IL-6 secretions ina concentration-dependent manner, but exe rted no effect on TNF alpha release. TNF alpha, IL-1 beta, and IL-6 secreti ons were inhibited by recombinant IL-10, but the cytokines release was upre gulated by anti-IL-10 monoclonal antibody. CONCLUSION: Both endogenous and exogenous nitric oxide and IL-10 had inhibitory effects on the LPS-induced TNF alpha, IL-1 beta, and IL-6 secretions in mouse AM.