| Objective To determine the effects of one lung ventilation on apoptosis of alveolar cell and the expression of Caspases-3, pulmonary surfactant protein A(SP-A) and pulmonary surfactant protein B (SP-B)in rats lung tissue.Methods Forty-Two Sprague-Dawley rats were randomly divided into: Control group (group C), Two lung ventilation group (group B), One lung ventilation group (group A). Group C were unventilated,according to different ventilation time, group A and group B were respectively divided into three subgroup A1, A2, A3and B1, B2, B3.The groups of A1, A2and A3performed one lung ventilation for0.5,1,1.5h respectively, which were all followed with two lung ventilation for0.5h. The groups of B1, B2and B3performed two lung ventilation for1,1.5and2h respectively. Artificial endotracheal tube was pushed into the right main bronchus to perform one lung ventilation.Lung pathological changes were examined under light microscopic;TdT-mediated dUTP nick end labeling (TUNEL) was used to define the extent and distribution of apoptosis in lung tissues;the expression of Caspase-3, SP-A and SP-B was determined by Western blot.Result As the time extend, group A and group B gradually showed intra-alveolar exudates,hemorrhage and interstitial edema in histopathology, and group A showed more seriuos. As compared with group C,TUNEL assay exhibited the incease of apoptosis on the lung tissues in group A2and group A3,and A2<A3(P<0.05).The Western blot study also showd Caspase-3,a key role in apopotsis,was expressed more in group A2and group A3,and A2<A3(P<0.05),the apoptosis index and Caspase-3levels were significantly higher in group A2,A3than those in group B2,B3. And as compared with group C, SP-A and SP-B were deceased in group A1,A2and A3(P<0.05), with the OLV time extension the levels decreased obviously(P<0.05),as compared with the subgroup in group B,the levels of SP-A and SP-B in group A1,A2and A3were respectively less than group B1,B2and B3(P<0.05).Conclusion As the time extend, one lung ventilation induces the structure changes in the lung tissue and apoptosis, and cause the levels of SP-A and SP-B in lung tissues decreased, compared with two lung ventilation, one lung ventilation can aggravate apoptosis in rat lungs,and the levels of SP-A and SP-B decreased obviously.We conclude that apoptosis and the pulmonary surfactant protein decreased may be the important factor of more serious lung injury caused by one lung ventilation. |
