RESUMO
Aim To study the effect of two racemic ketamine, S(+)-ketamine and R(-)-ketamine on stimulus-induced superoxide generation and intracellular calcium in vitro. Methods The stimulus-induced superoxide generation in human neutrophils was determined by using method of cytochrome C reduction. The intracellular calcium in human neutrophils was measured by chemiluminescence with Fura-2 loading. The phosphorylation of p47phox of NADPH oxidase in neutrophils was detected by Western blotting. Results S(+)-Ket and R(-)-Ket inhibited fMLP-induced superoxide generation in neutrophils in a concentration-dependent manner. In the case of PMA, S(+)-Ket inhibited PMA-induced superoxide generation and elevation of intracellular calcium of neutrophils in a concentration-dependent manner, whereas R(-)-Ket slightly increased PMA-induced superoxide generation and elevation of intracellular calcium of neutrophils. On the other hand S(+)-Ket inhibited the phosphorytion of p47phox of NADPH oxidase subunit,which R(-)-Ket was increased. EGTA can abolished the inhibition of S(+)-Ket on PMA-induced phosphorytion of p47phox.Conclusion S(+)-Ket inhibits the phosphorylation of p47phox of NADPH oxidase subunit and the superoxide generation in human neutrophils via PKC-calcium signal pathway.