Effect of propofol on SP-A in oleic acid-induced acute lung injury of rats

Objective To observe the effects of propofol on the expression of SP-A mRNA in Lung tissue of oleic acid-induced ALI rats.Methods Eighty male SD rats weighted 250～290g were anesthetized with intraperitoneal(i.p.) 20% urethane 6 ml·kg-1.Left common carotid artery and right internal jugular vein were cannulated for monitoring blood pressure and administration of reagents.The animals were randomly divided into 5 groups(n=16,in each group): groupⅠ:control group;groupⅡ: ALI group,oleic acid 250 μl·kg-1 i.v.;group Ⅲ: ALI+propofol 4 mg·kg-1·h-1;groupⅣ: ALI+ Propofol 8 mg·kg-1·h-1 and groupⅤ: ALI+propofol 16 mg·kg-1·h-1.After administration of oleic acid,the propofol at 4,8 and 16 mg·kg-1·h-1 was continuously injected for 4 h,then the animals were killed.Lung of eight animals in each group was immediately resected for determination of SP-A mRNA expressionby Reverse transcriptase-polymerase chain reaction analysis(RT-PCR) and Na+-K+-ATP ase activity was examined by biochemical assay.Lungs of other animals in each group were washed with icing saline.Then the BALF was sampled for counting WBC and its percentage of neutrophils.Results The expression of SP-AmRNA and the activity of Na+-K+-ATPase in Lung tissue was significantly decreased respectively,and WBC number and neutrophils percentage in BALF were significantly increased in group Ⅱ,compared with those of group Ⅰ.After admimstration of propofol,the activity of Na+-K+-ATP ase in lung tissne significantly increased and the WBC number and neutrophils percentage in BALF were markedly decreased compared with those of group Ⅱ.The expression of SP-A mRNA in lung tissue in group Ⅳ was significantly increased while the expression in group Ⅴ was significantly decreased,and there had no markedly changed in group Ⅲ,compared with those of group Ⅱ.Conclusion Propofol has a beneficial protective function on ALI induced by oleic acid through up-regulating SP-AmRNA in Lung tissue.