Effect of peroxisome proliferator-activated receptor α agonist on mechanical ventilation-induced lung injury in rats

Objective To investigate the effect of peroxisome proliferator-activated receptor α agonist Wy14643 on mechanical ventilation-induced lung injury in rats.Methods Thirty-two healthy male SD weighing 250-300 g were randomly divided into 4 groups(n = 8 each): group Ⅰ control(group C);group Ⅱ mechanical ventilation(group V)and group Ⅲ,Ⅳ pretreated with different doses of Wy14643(group W1 ,W2).The animals were anesthetized with intraperitoneal 3% pentobarbital 30 mg/kg and tracheostomized.The femoral artery and external jugular vein were cannulated for blood sampling and drug administration.Group C received no mechanical ventilation.In group V,W1 and W2 the animals were mechanically ventilated for 2 h(VT 40 ml/kg,RR40 bpm,I:E=1:2,FiO2 21%).In group W1 and W2 Wy14643 1 and 3 mg/kg were administered iv at 1 h before mechanical ventilation.Arterial blood samples were collected at 1 and 2 h of mechanical ventilation for determination of PaO2/FiO2.Serum SOD activity and MDA concentration were measured at the end of 2 h mechanical ventilation.The animals were then killed and the lungs removed for microscopic examination,lung lavage and W/D lung weight ratio.The MIP-2 and TNF-α concentrations in BALF were measured.Results Two hour mechanical ventilation significantly decreased serum SOD activity and increased serum MDA concentration,W/D lung weight ratio and TNF-α and MIP-2 concentrations in BALF as compared with group C.Wy14643 pretreatment significantly attenuated these mechanical ventilation-induced changes in group W1 and W2 in a dose-dependent manner.Conclusion Wy14643 can attenuate mechanical ventilation induced lung injury in rats and it is related to the dose. Key words: PPAR alpha; Respiratory distress syndrome,adult; Respiration,artificial