Effect of hydroxyethyl starch on TLR4 expression in the lung tissue in a rat model of acute lung injury

Abstract

Objective To investigate the effect of hydrexyethyl starch(HES)130/0.4 on Toll-like receptor 4(TLR4)mRNA and protein expression in the lung tissue in a rat model of acute lung injury(ALI)induced by lipopolysaccharide(LPS).Methods Thirty pathogen-free male SD rats weighing 250-300 g were randomly divided into5 groups(n=6 each): group Ⅰ normal control(group C);group Ⅱ ALI;group Ⅲ andⅣ HES 15 ml/kg or 30 ml/kg+ALI and group Ⅴ HES 30 ml/kg.The animals were anesthetized with intraperitoneal 10% chloral hydrate 300 mg/kg.The right internal jugular vein was cannulated for fluid and drug administration.ALI was induced by LPS 10 mg/kg iv in group Ⅱ,Ⅲ and Ⅳ.HES 130/0.4 was infused iv at0.2 ml/min at 1 min after LPS administration in group Ⅲ,Ⅳ and Ⅴ.The animals were killed at 6 h after IP LPS and the lungs were immediately removed for microscopic examination and detection of TLR4 mRNA and protein expression by RT-PCR and Western blotting.Results The TLR4 mRNA and protein expression was significantly higher in LPS group than in group C.HES 130/0.4 15 and 30 ml/kg significantly reduced the LPS-induced increase in TLR4 mRNA and protein expression in the lung tissue.There was no significant difference in TLR4mRNA and protein expression between the two ALI+HES groups(Ⅲ,Ⅳ).Conclusion HES 130/0.4 can inhibit ALI-induced ALI by depressing the TLR4 expression in the lung. Key words: Hetastarch; Respiratory distress syndrome,adult; Endotoxins; Toll-like receptor 4