THE EFFECT OF EMODIN ON THE INCREASE OF [Ca2+]i AND TNF-α PRODUCTION IN LIPOLYSACCHARIDE-STIMULATED RAT MACROPHAGES
大黄素影响巨噬细胞升高[Ca2+]i 和释放TNF-α的作用特征

To explore the role of emodin on increase in Ca2+]i and TNF-α production in normal and lipopolysaccharide (LPS)-stimulated rat peritoneal macrophages (PMφ), TNF-α production was determined using TNF-α-sensitive L929 cell line and by MTT method and the kinetics of intracellular free Ca2+ concentration (Ca2+]i) in a single cell were monitored continuously by confocal laser scanning microscope. The results showed that 10-5 mol/L emodin could elevate TNF-α production slightly, and caused forming low amplitude Ca2+]ioscillation in normal single PMφ. Emodin could inhibit both excessive release of TNF-α and increase in Ca2+]i when PMφ was stimulated by LPS. 10-5 mol/L emodin inhibited TNF-α production by 50% and Ca2+]i increase by 68% respectively. Interestingly, emodin could transform the high amplitude "plateau-like" Ca2+]i induced by LPS into fluctuation that has low amplitude. These results indicate that the biphase characteristics of modulation of Emodin on TNF-α production correlate with Ca2+]i changing. The modulation of emodin on Ca2+]i may be a main way that emodin inhibits TNF-α production in LPS stimulated PMφ.