Changes of plasma TNF-? and IL-6 level in LPS-heat co-stressed rats / 第三军医大学学报

ABSTRACT

Objective To investigate the effects of co-exposure to LPS and heat on plasma tumor necrosis factor-? (TNF-?) and interleukin-6 (IL-6) in rats. Methods Eighty male pathogen-free Wistar rats were randomly assigned to 4 groups saline-injected normothermic control (group C), saline-injected heat exposed (group H), LPS-injected normothermic control (group L), LPS-injected heat exposed (group HL). Rectal temperature (Tr), heart rate (HR), mean arterial pressure (MAP), and respiratory rate (RR) were continually monitored. Plasma levels of TNF-? and IL-6 were determined at 0, 40, 80, 120 min after treatment. Results The rats in group HL displayed significantly higher values of Tr , HR , and RR and lower values of MAP than that of group C at 120 min. There was a significant difference in the values of HR and MAP between group HL and the other 3 groups at the same time point. The rats in group HL displayed an early rise in levels of plasma TNF-?, IL-6 at 40 min. The significant elevation of the peak TNF-? level at 80 min in group HL was observed. Plasma IL-6 hyperexpression was shown in rats in group HL which was significantly higher than the other 3 groups at the same time point. Conclusion Co-exposure to LPS and heat induces the rat to develop and augment systemic inflammatory response syndrome.