Effect of mild hypothermia on lungs of septic rats

Objective: To investigate the effect of mild hypothermia on the lung injury of septic rats.Methods: Twenty-four Wistar rats were randomly divided into normal control group,lipopolysaccharide(LPS) group,and mild hypothermia(MHT) group.The rats in normal control group and LPS group were intraperitoneally injected with normal saline and LPS,respectively.The body temperature of rats in MHT group was kept at 32 to 33 ℃ for 3 hours after the intraperitoneal injection of LPS.The expression of tumor necrosis factor-α(TNF-α) mR-NA was determined by reverse transcriptase polymerase chain reaction,and the ultrastructure of lungs was observed under transmission elec-tronic microscope.Results: The expressions of TNF-α mRNA in lung tissues 1,2,and 3 hours after the injection of normal saline or LPS were 0.625±0.009,0.631±0.007,and 0.612±0.011 in normal control group,1.029±0.055,1.132±0.068,and 1.107±0.044 in LPS group,and 0.835±0.041,1.056±0.037,1.056±0.032 in MHT group.Compared with the normal control group,the expressions of TNF-α mRNA in LPS and MHT groups were significantly higher(P 0.05).Compared with LPS group,the expressions of TNF-α mRNA were sig-nificantly lower in MHT group,and lung injury was less severe.Conclusion: Mild hypothermia could decrease TNF-α mRNA expression in the lung tissue of septic rats,and thus decrease the severity of lung injury to some extent.