Effects of vitamin C on expression of nitric oxide synthase of alveolar macrophage treated with Ni₂O₃

  Objective   To study the effects of vitamin C on the expression of NOS of alveolar macrophages exposure to Ni₂O₃ in vitro.

  Methods   The alveolar macrophages were cultured by exposure to Ni₂O₃ in vitro.Meanwhile, vitamin C(25, 50 and 100 μmol/ L)were added in the medium, respectively.The detection of active oxygen, nitric oxide(NO)and activity of nitric oxide synthase (NOS)in alveolar macrophages were carr ied out.Reverse transcription polymerase chain reaction was used to check the mRNA level of induced nitric oxide synthase.

  Results   Vitamin C could decrease mortality and increase survival activity of alveolar macrophages.Active oxygen, NO and NOS activity decreased in the same time.The expression of iNOS was dramatically suppressed in the same time.

  Conclusion   T he expression of iNOS was induced by Ni₂O₃ in alveolar macrophages, which gave rise to producing a great amount of NO and resulted in the lipid peroxidation of cells.Vitamin C could antagonize the lipid peroxidation of alveolar macrophage induced by Ni₂O₃, which probably due to its antioxidant property.