Effects Of Deferoxamine On Pulmonary Surfactant And Antioxidant Enzymes In Rats With Lung Injury Induced By Short-term Hyperoxia

Objective:To investigate the effects of deferoxamine on pulmonary surfactant and antioxidant enzymes in rats with lung injury induced by short-term hyperoxia.Methods:Twenty-four sprague dawley rats（weighing 180-220g）were randomly divided into 3 groups（n=8/group）:mechanical ventilated with normoxia group（group MV）,with hyperoxia group（group HMV）,or with hyperoxia+DFO group（group HMV+DFO）.Tracheotomy and catheterization were carried out under general anesthesia.The rats in group MV were ventilated with air（FiO₂=21%）,groups HMV and HMV+DFO were ventilated with oxygen（FiO₂=90%）for 4 h.Meanwhile,groups MV and HMV were infused normal saline（1 ml/h）via tail vein,group HMV+DFO were infused the same volume of DFO（200 mg/kg,1 ml/h）intravenously.The left carotid artery was punctured and cannulated under a sterile condition,and artery blood was taken for blood gas analysis at 2 h and 4 h of ventilation,to monitor arterial partial pressure of oxygen（PaO₂）and partial pressure of carbon dioxide（PaCO₂）,adjust respiratory rate and calculate oxygenation index（OI）.The bronchoalveolar lavage fluid（BALF）was prepared in left lung after 4 h of ventilation.The right lung was taken to make tissue homogenate,measure the wet/dry weight（W/D）ratio,make pathological section and the injury level was scored.The content of pulmonary surfactant protein C（SP-C）,pulmonary surfactant protein D（SP-D）,the activity of glutathione reductase（GR）and xanthine oxidase（XOD）were detected in BALF and lung homogenate by ELISA,respectively.Results:The result of blood gas analysis show:PaO₂ in groups HMV and HMV+DFO were significantly higher than those of the group MV（P<0.05）,and the OI were significantly lower.While PaO₂ and OI between groups HMV+DFO and HMV did not differ significantly.Compared with group MV,the content of SP-C,SP-D and the activity of GR in groups HMV and HMV+DFO were lower（P<0.05）,the activity of XOD,W/D and pathological evaluation were much higher（P<0.05）;Compared with group HMV,the content of SP-C,SP-D and the activity of GR in group HMV+DFO were higher（P<0.05）,the activity of XOD,W/D and pathological evaluation were lower（P<0.05）.Conclusions:Mechanical ventilation with hyperoxia for 4 h could induce oxidative injury of the lungs,accompanied by a dramatic reduction in the concentrations of SP-C and SP-D.DFO infusion has an effect of increasing SP-C,SP-D content and alleviating lung injury,and the mechanism is related to the increased GR and decreased XOD activity.