Effects of palmitic acid,oleic acid and VLDL on the sensitivity to endotoxin of macrophages

Objective To investigate the effects of palmitic acid, oleic acid and very low density lipoprotein (VLDL) on the sensitivity to endotoxin of macrophages. Methods After incubated with various concentrations of palmitic acid, oleic acid or VLDL, the RAW264.7 macrophages (murine macrophage cell line) were stimulated by 100 ng/ml endotoxin, and the TNFα levels in culture medium were measured by radioimmunoassay. The effects of 0.125 mmol/L palmitic acid, 0.125 mmol/L oleic acid and 7.5 mmol/L VLDL on the activity of NFκB of RAW264.7 macrophages were observed by immunohistochemistry. Results Incubated by palmitic acid, oleic acid or VLDL for 24 hours, TNFa production of RAW264.7 macrophages after stimulation by 100 ng/ml endotoxin was increased and was dependent on the lipid concentrations. Exposure to palmitic acid, oleic acid or VLDL for 24 hours significantly increased the rates of positive stain of NFκB of RAW264.7 macrophages (control 5.8%±3.4%, palmitic acid 52.7%±10.5%** oleic acid 25.2%±8.3%**, VLDL 17.3%±8.7%*,**P0.01 vs control,*P0.05 vs control).Conclusion Palmitic acid, oleic acid and VLDL might increased the sensitivity to endotoxin of macrophages which was related to the activation of NFκB of macrophages.