Balis J U, Pagast P, McKeever L, Shelley S
Lab Invest. 1975 Sep;33(3):289-97.
The reactions of the fetal and newborn lung to in utero injury were investigated in rabbits using as a model maternal administration of Escherichia coli endotoxin, 2 to 4 mug per kg. of body weight, injected intravenously at the 29th gestational day. At 6 hours after endotoxin injection, the lung revealed diffuse alveolar damage-sparing type II cells which appeared resistant to injury but more mature than type II cells from control lungs. These changes were followed by a reparative phase which over a 2-day period resulted in increased interstitial cellularity, replacement of the damaged type I cells by proliferated type II cells, and marked intraalveolar accumulation of myelin figures. The above reactions were associated with an average increase of 100 per cent in the phospholipid content of the surfactant fraction isolated from lung washing. Postnatally, the lungs showed structural changes resembling those seen in hyaline membrane disease of the newborn. The findings suggest that the response of the alveolar epithelim to injury inudced late in gestation follows a pattern similar to that described previously in adult lung, and is assoicated with in utero increased release of surfactant. It is proposed that alveolar injury and repair, including reduction of the intracellular surfactant reservoir occurring prior to breathing, may interfere postnatally with formation and maintenance of a normal surfactant layer, thereby predisposing to respiratory distress.
在兔子身上研究了胎儿和新生儿肺对子宫内损伤的反应，采用的模型是在妊娠第29天经静脉给母体注射每千克体重2至4微克的大肠杆菌内毒素。在内毒素注射后6小时，肺呈现弥漫性肺泡损伤，II型细胞未受损伤，这些细胞似乎对损伤有抵抗力，且比对照肺的II型细胞更成熟。随后进入修复阶段，在2天的时间里，间质细胞增多，受损的I型细胞被增殖的II型细胞取代，肺泡内出现大量髓磷脂小体。上述反应与从肺灌洗中分离出的表面活性物质部分的磷脂含量平均增加100%有关。出生后，肺显示出与新生儿透明膜病相似的结构变化。研究结果表明，妊娠后期肺泡上皮对损伤的反应模式与先前在成年肺中描述的相似，并且与子宫内表面活性物质释放增加有关。有人提出，肺泡损伤和修复，包括呼吸前细胞内表面活性物质储备的减少，可能在出生后干扰正常表面活性物质层的形成和维持，从而易导致呼吸窘迫。
