ABSTRACT
Objective To evaluate the effect of 6% hydroxyethyl starch (HES) 200/0.5 on the pulmonary capillary permeability in oleic acid induced acute lung injury (ALI) and investigate the possible mechanism of the therapeutic effect of HES. Methods Forty male SD rats weighing 280-370 g were randomly divided into four groups: group I balanced solution (control); group II 6% HES 200/0.5; group III gelatin and group IV dextran 40. The animals were anesthetized with intraperitoneal 3% pentobarbital 30-40 mg?kg-1 . Right external jugular vein was cannulated. Oleic acid 0.06 ml?kg-1 was given iv.10 ml?kg-1 of the above-mentioned different solutions was infused over 1.5 h in the four groups. Then 0.5% Evan's blue 1ml was injected iv. Four hours later the animals were sacrificed and lungs removed for pathologic examination under microscope, and determination of lung water content [ (wet weight -dry weight)/wet weight ? 100% ] . Lung Evan's blue content was determined by formamide extracting method. Lung MDA content and MPO activity were also determined.Results Lung water and Evan's blue contents were significantly lower in group II than those in any other groups. MPO activity and MDA level in group II were lowest among the four groups. Conclusions HES can decrease pulmonary capillary permeability, attentuate pulmonary edema and lung injury, and depress MPO activity and MDA level. The underlying mechanism may be due to its depressant effect on PMN aggregation and lipid peroxidation.