Effects of lidocaine on expression of HMGB1 mRNA induced by lipopolysaccharide in rat peritoneal macrophages

Objective To investigate the effects of lidocaine on expression of high mobility group box-1(HMGB1) protein mRNA induced by lipopolysaccharide(LPS) in rat peritoneal macrophages.Methods Peritoneal macrophages obtained from male Wistar rats were incubated in six-well tissue culture plates for 3-5 days before stimulated with LPS and treated with lidocaine.The rats were divided into 4 groups of LPS,L1,L2 and L3.After washing with serum-free RPMI-1640 culture medium,all macrophages were incubated with 2.0 ml serum-free RPMI-1640 culture medium.The macrophages in group LPS were stimulated with LPS in a concentration of 100 ng/ml,those in group L1 with lidocaine in a concentration of 20 μg/ml 30 minutes before LPS stimulation,those in group L2 with lidocaine in the same doses 30 minutes after LPS stimulation,and those in group L3 with lidocaine in the same doses at 30 min,6 h,12 h,18 h after LPS stimulation.Then all macrophages were incubated for 24 hours after LPS stimulation.The expression of HMGB1 mRNA in the macrophages were detectned by RT-PCR.Results Compared to group LPS,the expression of LPS-induced HMGB1 mRNA was significantly inhibited in a certain degree by lidocaine in groups of L1,L2 and L3,which was more in group L3 than that in group L2 or L1(P0.01).Conclusion Lidocaine can significantly inhibit the expression of HMGB1 mRNA induced by LPS in rat peritoneal macrophages.