Sensitivity of bacteria to NaNO2 and to L-arginine-dependent system in murine macrophages.

Sensitivity of bacteria to NO2-/NO and to L-arginine-dependent system in murine macrophages was tested. The growth of all bacteria tested, Salmonella typhimurium, Pseudomonas aeruginosa and Staphylococcus epidermidis, was significantly inhibited by NaNO2 at the concentration of 5 to 10 mM. However, L-arginine-dependent effector mechanism of LPS-activated murine macrophages was ineffective in killing these bacteria. It seems that the concentration of NO2-/NO in phagolysosome in the activated macrophages is insufficient to kill the bacteria in situ. We concluded that L-arginine-dependent effector mechanism can hardly work on bacteria killing in activated macrophages.