Influence of dexamethasone on the lung tissue cell apoptosis in rabbits with VILI

Objective To explore the influence of dexamethasone on the lung tissue cell apoptosis in rabbits with VILI. Methods Thirty healthy male rabbits were randomly divided into three groups (10 rabbits in each group): control group (groupⅠ), high tidal volume mechanical ventilation group (groupⅡ) and dexamethasone group (group Ⅲ). GroupⅠ applied no mechanical ventilation after intubation, with intravenous injection of 5 ml physiological saline. GroupⅡ and group Ⅲ were given mechanical ventilation (tidal volume: 25 ml/kg; frequency: 30 times/min, respiratory absorption ratio: 1:3; PEEP: 0 cmH 2 O; FiO 2 : 21%; ventilation Time: 24 h). Group Ⅱ were injected intravenously with 5 ml physiological saline when starting mechanical ventilation. Group Ⅲ were injected intravenously 5 mg/kg dexamethasone. Cell apoptosis in lung tissue was detected by means of annexin V/PI staining method. The wet and dry weight (W/D) ratio of lung tissue was calculated, and lung tissue sections were prepared for biopsies. Results Lung tissue cell apoptosis rate and W/D in group Ⅱ, group Ⅲ was significantly higher that those in group Ⅰ (P0.001), which was significantly lower in group Ⅲ than group Ⅱ (P0.01). According to lung tissue biopsy, lung tissue visible pulmonary interstitial and alveolar spaceedema, pulmonary inflammatory cell infiltration could be observed in group Ⅱ, and the pulmonary edema was weaker in group Ⅲ than group Ⅱ. Conclusion Dexamethasone can inhibit cell apoptosis in lung tissue, thus prevention VILI.