Devaskar U P, Govindrajan R, Heyman S, Sosenko I R, deMello D E
Department of Pediatrics, Saint Louis University Health Sciences Center, Mo, USA.
Biol Neonate. 1996;70(2):101-7. doi: 10.1159/000244354.
Maternal administration of thyrotropin-releasing hormone, alone or in combination with corticosteroid, accelerates functional, morphologic and biochemical fetal lung maturation. However, the dose-response relationship of maternal thyrotropin-releasing hormone treatment and acceleration of fetal lung ultrastructural maturation or disaturated phosphatidylcholine content has not been investigated. We administered (i.p.) saline or thyrotropin-releasing hormone (0.2, 0.4 or 0.6 mg/kg/dose) to the pregnant Balb/c mouse on days 16 and 17 (b.i.d.) and on day 18 of gestation (1 h prior to killing). Morphometric ultrastructural analysis and quantitation of disaturated phosphatidylcholine content was done on the 18-day gestation fetal lung. Maternal thyrotropin-releasing hormone treatment resulted in an increase in the number of lamellar bodies and depletion of glycogen in fetal lung type II cells, and an increase in the lung airspace to parenchymal ratio. In addition, a striking difference in the pattern of lung growth was noted in the thyrotropin-releasing-hormone-treated (0.4 and 0.6 mg/kg/dose) groups. These lungs had larger air spaces, thinner alveolar septae and more air-blood barriers. Maternal thyrotropin-releasing hormone treatment did not influence fetal lung disaturated phosphatidylcholine content. We conclude that in the mouse, maternal thyrotropin-releasing hormone treatment enhances fetal lung structural maturation and propose that thyrotropin-releasing hormone plays a role in mammalian fetal lung growth.
母体单独或联合使用皮质类固醇给予促甲状腺激素释放激素，可加速胎儿肺的功能、形态和生化成熟。然而，母体促甲状腺激素释放激素治疗与胎儿肺超微结构成熟加速或二饱和磷脂酰胆碱含量之间的剂量反应关系尚未得到研究。我们在妊娠第16天和第17天（每日两次）以及妊娠第18天（处死前1小时）经腹腔给怀孕的Balb/c小鼠注射生理盐水或促甲状腺激素释放激素（0.2、0.4或0.6mg/kg/剂量）。对妊娠18天的胎儿肺进行形态计量学超微结构分析和二饱和磷脂酰胆碱含量定量。母体促甲状腺激素释放激素治疗导致胎儿肺II型细胞中板层小体数量增加、糖原耗竭，以及肺气腔与实质比例增加。此外，在促甲状腺激素释放激素治疗组（0.4和0.6mg/kg/剂量）中，观察到肺生长模式存在显著差异。这些肺的气腔更大、肺泡间隔更薄且气血屏障更多。母体促甲状腺激素释放激素治疗不影响胎儿肺二饱和磷脂酰胆碱含量。我们得出结论，在小鼠中，母体促甲状腺激素释放激素治疗可增强胎儿肺的结构成熟，并提出促甲状腺激素释放激素在哺乳动物胎儿肺生长中起作用。
