家兔烟雾吸入性损伤早期肺表面活性物质存在形式的改变及意义

目的　观察肺表面活性物质 (PS)存在形式 (大聚体和小聚体 )的改变对吸入性损伤早期PS活性下降的影响。　方法　将家兔随机分为烟雾吸入性损伤前及伤后 0 .5、2 .0、6 .0、1 2 .0h共 5组 ,每组 8只。收集各组支气管肺泡灌洗液 ,离心后分别留取上清液 (小聚体 )和沉淀物 (大聚体 ) ,测定PS组织成分中总磷脂、磷脂酰胆碱、总蛋白、白蛋白在上述两种形式中的含量。　结果　伤前组家兔小聚体中总磷脂、磷脂酰胆碱、总蛋白、白蛋白含量及磷脂酰胆碱占总磷脂的百分含量分别为 (2 .2 3± 0 .4 0 )、(1 .5 4± 0 .1 1 )、(1 6 .6 7± 1 .34)、(3.6 5± 0 .1 5 )g/L和 (77.2± 3.7) %,伤后 6h组的小聚体中以上指标各为 (3 1 5± 0 .30 )、(1 .77± 0 .0 8)、(1 0 6 .5 9± 5 .5 0 )、(1 1 .2 1± 0 .92 )g/L和 (5 7.2± 3.5 ) %。与伤前组比较 ,伤后各组PS组分在大聚体中差异无显著性意义 (P >0.0 5 )。在小聚体中 ,白蛋白、总蛋白含量在较伤前显著增多 (P <0.0 1),并随时间的延长呈上升趋势 ;磷脂酰胆碱占总磷脂的百分含量随时间延长呈下降趋势。　结论　小聚体与大聚体之间的比值显著增高 ,可能是引起吸入性损伤早期PS活性下降并导致急性肺损伤的一个重要因素。

The significance of the change of the subfractions in existence of the pulmonary surfactant in rabbits with smoke inhalation injury during early postburn stage

OBJECTIVE: To investigate the change of the subfractions in existence (big and small polymers) of pulmonary surfactant (PS) and their influence on the decrease in PS activity during early postburn stage. METHODS: Forty rabbits were employed in the study and were randomly divided into pre-burn, 0.5 postburn hour (PBH), 2 PBH, 6 PBH and 12 PBH groups with 8 in each group. The BALF (bronchial alveolar lavage fluid) was harvested from each rabbit. The BALF samples were centrifuged, and the supernatant (small polymer) and precipitation (big polymer) were harvested for the determination of the contents of the total phospholipids, lecithin, total protein, and albumin in both polymers. RESULTS: Compared with those in pre-burn group, the above chemical contents of PS in big polymer exhibited no change after burn (P > 0.05), but the contents of albumin and total protein increased obviously in small polymer (P < 0.01). In addition, all the contents in the small polymer increased with the elapse of time. The percentage of lecithin in total phospholipids in small polymers decreased along with the passage of time. The pre-burn contents of total phospholipids, lecithin, TP, albumin, and the percentage of lecithin in total phospholipid in small polymer were (2.23 +/- 0.40),(1.54 +/- 0.11), (16.67 +/- 1.34), (3.65 +/- 0.15) mg/ml and (77.2 +/- 3.7)%, respectively. The above indices in small polymer were (3.15 +/- 0.30), (1.77 +/- 0.08), (106.59 +/- 5.50), (11.21 +/- 0.92) mg/ml and (57.2 +/- 3.5)% respectively at 6PBH. CONCLUSION: The ratio of small to big polymers increased obviously, which might be an important factor in inducing the decrease in PS activity during early postburn stage leading finally to pulmonary injury.