Effects of cell apoptosis on ventilator-induced lung injury

Objective: To observe the effects of cell apoptosis on ventilator-induced lung injury(VILI) and discuss the mechanisms of VILI. Methods: Fifty healthy male Wister rats were randomly divided into control group and lung injured group.The control group was not given mechanical ventilation after intubation,whereas the lung-injured group was given mechanical ventilation(tidal volume:20ml·kg-1,frequency: 50 times min-1,inspiratory and expiratory rate: 1∶3,FiO2:21%,ventilation time: 5 hours).Changes of arterial partial pressure of oxygen before and after experiment were observed.Cell apoptosis in lung tissue and bronchia alveolus lavage fluid was detected by means of annexin V/PI staining method.The whole left lung of the rats from two groups was taken wet weight,and dry weight was taken after being put into an oven and baked with 80 ℃ for 24 hours,then calculating the wet and dry weight(W/D) ratio of lung tissue.Lung tissue sections were prepared for biopsies.Results: There were no significant differences in arterial partial pressure of oxygen between the two groups(P0.05).Cell apoptosis in lung tissue and bronchia alveolus lavage fluid significantly increased in lung injured group(P0.01).The W/D ratio of lung tissue in lung injured group was higher than that in the control group(P0.01).Lung tissue edema could be fined in lung tissue biopsy of lung injured group.Conclusions: Mechanical ventilation could cause lung injury.Cell apoptosis may play an important role in the occurrence and development of ventilator induced lung injury.