Effects of lipopolysaccharide on IL-10, IL-6 and TNF-α levels in radiation-exposed mice

Objective To investigate the effects of lipopolysaccharide (LPS) on interleukin-10(IL10),interleukin-6(IL-6) and tumor necrosis factor-α(TNF-α) levels in mice exposed whole body to 6 Gy γ-ray radiation once.Methods The mice were divided into sham-irradiation group and irradiation group.Mice in sham-irradiation group accepted no irradiation,while mice in irradiation group accepted 6 Gy whole body irradiation at dose rate of 0.8 Gy/min.Mice in LPS treated group accepted intraperitoneal injection of LPS (20 mg/kg) at 10 weeks after irradiation,while mice in control group were accepted intraperitoneal injection of saline.The peripheral blood was collected by eyeballs enucleation after 1 h and 24 h respectively,then IL10,IL-6 and TNF-α levels were detected by enzyme-linked immunoassay.Results Compared to control group,the levels of IL-10,IL-6 and TNF-α in blood serum increased at 1 h and 24 h after LPS injection both in sham-irradiation group (t=7.31,P＜0.01; t=2.71,P＜0.05; t=15.09,P＜0.01 ) and irradiation group(t＝4.14,7.18 and 5.14,all P＜0.01 ).Compared to sham-irradiation group,the level of IL-10 increased 19.9％ at 24 h after LPS injection in irradiation group(t=2.84,P＜0.05),while the levels of TNF-α and IL-6 had no significant differences between sham-irradiation group and irradiation group.Conclusions The immune system of mice had not entirely recovered at 10 weeks after 6 Gy y-ray irradiation.After LPS injection,there was difference of anti-infection ability between sham-irradiation group and irradiation group.The effects of LPS on cytokines IL-10,IL-6 and TNF-α levels in radiation-exposed mice need to be further explored. Key words: Lipopolysaccharides;  Gamma rays;  Interleukin-10;  Interleukin-6;  Tumor necros is factor-alpha