家兔烟雾吸入性损伤早期肺表面张力及表面活性物质蛋白B组织含量的改变

The changes in the pulmonary surface tension and the tissue content of surfactant substance protein B during early post-injury stage in rabbits inflicted with smoke inhalation injury

目的 研究家兔烟雾吸入性损伤早期肺表面张力及表面活性物质蛋白B(PSP B)的变化规律。 方法 将 32只家兔制成烟雾吸入性损伤模型 ,设为致伤组 ,于伤后 0 .5、2 .0、6 .0、12 .0h处死 ,每时相点 8只 ;另处死 8只正常家兔作为正常对照组。获取各组家兔支气管肺泡灌洗液(BALF),加入 0 .5、1.0、3.0mlPSP B抗体 ,检测加入抗体前后BALF最大表面张力 (Tmax)、最小表面张力 (Tmin)、滞后环面积 (HS)的变化。取各组家兔肺组织 ,应用免疫组织化学与原位杂交技术检测Ⅱ型上皮细胞中PSP B及其mRNA含量的改变。 结果 3种剂量PSP B抗体作用前后 ,各组各时相点Tmax无明显改变 (P >0.0 5)。3.0mlPSP B抗体作用后 ,致伤组伤后 2 .0、6 .0、12 .0hBALF的Tmin各为 3.5 99、3.74 8、3.5 14Pa,明显高于各自的阻断前值 (2 .85 1、3.0 0 0、3.130Pa,P <0.0 5 )。HS的变化情况同Tmin。致伤组伤后 2 .0、6 .0、12 .0h肺组织Ⅱ型上皮细胞中PSP B明显减少 ,PSP BmRNA表达无明显变化。 结论 家兔烟雾吸入性损伤早期肺表面活性物质活性降低 ,PSP B合成无明显改变但分泌能力增强 ,可能对肺组织具有一定的早期保护作用。

Objective To investigate the changes in the pulmonary surface tension and the tissue content of surfactant substance protein B (SP-B) in rabbits during early post-injury stage after smoke inhalation injury. Methods Thirty-two healthy rabbits inflicted with smoke inhalation injury were employed in the study as injury group, and they were sacrificed at 0.5, 2.0, 6.0, 12.0 post injury hours (PIH), with 8 rabbits at each time point. Another 8 rabbits were assigned to normal control group. The pulmonary tissue samples of the rabbits in each group were harvested for the collection of bronchial-alveolar lavage fluid (BALF). The changes in maximal tension (Tmax), minimal tension (Tmin) and hysteresis square(HS) of BALF were measured after the addition of 0.5, 1.0 and 3.0 ml of SP-B antibody into the BALF of the rabbits in each group. The changes in SP-B and SP-B mRNA contents in rabbit pulmonary tissue of each group were assessed with immunohistochemistry and in situ hybridization techniques, respectively. Results There was no obvious difference in Tmax in BALF of each group or at each time point before and after the action of different concentrations of SP-B antibody in BALF ( P >0.05). But the Tmin in injury group at 2, 6 and 12 PIH was much higher than that before the addition of the antibody ( P < 0.05). And the change in HS was similar to that in Tmin. The SP-B content in alveolar type II epithelial cells (AT-II) was decreased significantly at 2, 6 and 12 PIH, whereas the expression in SP-B mRNA exhibited no change. Conclusion There was no obvious change in SP-B synthesis by AT-II in the lung tissue of the rabbits inflicted with smoke inhalation injury during early post injury stage. The increase of SP-B secretion from AT-II cells might be beneficial to the early protection of pulmonary tissue of the rabbits with smoke inhalation injury.