Influence of Lipid Emulsions on the Interleukin-6 Expression of Lung Tissues and Apoptosis of Alveolar Epithelial Cells in Acute Lung Injury Rats Induced by Endotoxin

Objective To compare the influence of three kinds of lipid emulsions on interleukin-6(IL-6) expression of lung tissues and apoptosis of alveolar epithelial cells in acute lung injury(ALI) rats induced by LPS.Methods One hundred young Sprague-Dawley(SD) rats were divided into 4 groups by random number table method:control group,model group,Intralipid group,Clinoleic group and Omegaven group,20 in each group.For 7 consecutive days,control group and model group were injected with normal saline,Intralipid group was injected with fat emulsion injection(C14-24)(Intralipid),Clinoleic group was injected with long chain fat emulsion injection(OO)(Clinoleic),Omegaven group was injected with ω-3 fish oil fat emulsion injection(Omegaven).ALI model was established 8 hours before taking specimens(normal saline was dropped into windpipe of control group,LPS solution was dropped into windpipe of the other 4 groups).The pathologic changes of lung tissues were observed,IL-6 mRNA expression level of lung tissues,IL-6 level in BALF and apoptosis index(AI) of alveolar epithelial cells were measured among all rats.Results There was significant inflammatory in lungs tissue of 4 groups of rats(except for control group).The expression level of IL-6 mRNA of lung tissues and the level of IL-6 in BALF in model group and Intralipid group were significantly higher than those in Clinoleic group and Omegaven group(P 0.05),but there was no significant difference in the expression level of IL-6 mRNA of lung tissues and the level of IL-6 in BALF between Clinoleic group and Omegaven group(P 0.05).AI of alveolar epithelial cells in Clinoleic group and Omegaven group were significantly lower than those in model group and Intralipid group(P 0.05),but there was no significant difference in AI of alveolar epithelial cells between Clinoleic group and Omegaven group(P 0.05).Conclusion Clinoleic and Omegaven can relieve inflammation by downregulating the concentrations of IL-6,and can reduce the alveolar epithelial cell apoptosis in rats with acute lung injury,thus have some effect of anti-inflammation.