Shima H, Guarino N, Puri P
Children's Research Centre, Our Lady's Hospital for Sick Children, Dublin, Ireland.
Pediatr Surg Int. 2000;16(7):473-7. doi: 10.1007/s003830000427.
The hypoplastic lung in congenital diaphragmatic hernia (CDH) has both a quantitative and qualitative reduction in surfactant. Recently, the role of oxygen (O2) as a regulator of pulmonary surfactant-associated protein (SP) gene expression has been reported. The mRNA level of SP has been demonstrated to be increased in the lungs of animals exposed to hyperoxia. The aim of this study was to investigate SP mRNA expression in hypoplastic CDH lung in rats during mechanical ventilation in order to determine the effect of O2 on SP synthesis in CDH. A CDH model was induced in pregnant rats following administration of nitrofen. The newborn rats with CDH and controls were intubated and ventilated. Ventilation was continued for 6 h under 100% oxygen. Reverse-transcription polymerase chain reaction (RT-PCR) was performed to evaluate the relative amounts of mRNA expression of SP-A, SP-B, SP-C, and SP-D. Relative amounts of SP-A, SP-B, and SP-D mRNA expression in CDH lung were significantly decreased compared to controls at birth and 6 h after ventilation. There was no significant difference in SP-C mRNA expression between CDH animals and controls. Upregulated mRNA expression of SP-A, SP-B, and SP-D in lungs of control animals at 6 h after ventilation suggests that oxygenation accelerates postnatal SP synthesis in normal lungs. The inability of O2 to increase SP mRNA expression in hypoplastic CDH lung suggests that the hypoplastic lung is not responsive to increased oxygenation for the synthesis of SP.
先天性膈疝（CDH）中的肺发育不全存在表面活性剂的定量和定性减少。最近，有报道称氧气（O2）作为肺表面活性物质相关蛋白（SP）基因表达的调节因子发挥作用。已证明在暴露于高氧的动物肺中，SP的mRNA水平会升高。本研究的目的是调查大鼠机械通气期间CDH肺发育不全中SP mRNA的表达，以确定O2对CDH中SP合成的影响。在给予硝基芬后诱导怀孕大鼠建立CDH模型。对患有CDH的新生大鼠和对照组进行插管和通气。在100%氧气下持续通气6小时。进行逆转录聚合酶链反应（RT-PCR）以评估SP-A、SP-B、SP-C和SP-D的mRNA表达相对量。与出生时和通气后6小时的对照组相比，CDH肺中SP-A、SP-B和SP-D mRNA表达的相对量显著降低。CDH动物和对照组之间的SP-C mRNA表达没有显著差异。通气后6小时对照组动物肺中SP-A、SP-B和SP-D的mRNA表达上调表明，正常肺中的氧合作用加速了出生后SP的合成。O2无法增加发育不全的CDH肺中SP mRNA的表达，这表明发育不全的肺对增加的氧合作用合成SP没有反应。
