The changes of pulmonary surfactant assodated protein A in BALF with lung injury in rats with blast injury and blast injury combined with hypmia / 中华急诊医学杂志

ABSTRACT

Objective To investigate the changes of surfactant associated protein A (ST-A) concentration inBALF and its relatiomhips with pulmonary injury after blast injury and blast injury combined with hypoxia. MethodTotally 131 Wistar rats (purchased from animal center of research Institute of Surgery, Daping Hospital, ThirdMilitary Medical University) were randomly divided into four groups blast injury group ( BI group), blast injurycombined with hypoxia group Ⅰ (BAg Ⅰ group), blast injury combined with hypoxia group Ⅱ (BA Ⅱ group) andnormal control group. After blast injury was made by KST - Ⅰ bio-shock tube, rats of BA Ⅰ and BA Ⅱ groups wereput into hypoxia cabins immediately, where gas mixtures of 12.5% and 10.0% oxygeon were given, respectively.Rats were sacrificed at 1, 3 and 6 hours after injury for gross anatomic examination, light and electron microscopeobservation and lung water determination. The level of SP-A in BALF was detected by Western blot. The data wereprocessed by t test or Chi-square test. Results The respiration increased with shortness of breath and dysphoria inrats of BA Ⅰ and BA Ⅱ groups, and obvious cyanosis on the lips and nose in rats of BA Ⅱ group after blast injury.The lung water in rats of all injury groups was significantly higher than that in normal control group (P<0.05).Gross anatomy changes were mainly pulmonary bleeding and edema. Under light microscope, incrassation of alveo-lar wall, bleeding in alveolar and mesenchyme edema were found. Whereas under electron microscope, breakageof alveolar wall and decrease of lamellar bodies in type Ⅱ cell were observed. All these changes were most obviousin BA Ⅱ group followed by BA Ⅰ and BI groups in severity decling order, with mortality rate of 37.5%, 11.1%and 2.1% respectively at 6 hours (P<0.01). The SP-A level in BALF decreased significantly (P<0.01) andhad a good negative relationship with the lung water after injury (r=0.796, P<0.001 ). Conclusions Blastinjury combined with hypoxia significantly deteriorates the lung injury. More severe and longer hypoxia may resultin more severe lung injury and higher mortality rate. A decrease in SP-A value in BALF shows a good negative re-lationship with the pulmonary edema. The SP-A can be a good indicator for lung injury severity after blast injuryand blast injury combined with hypoxia.