Ikegami M, Polk D, Tabor B, Lewis J, Yamada T, Jobe A
Department of Pediatrics, Harbor-UCLA Medical Center, Torrance 90509.
J Appl Physiol (1985). 1991 May;70(5):2268-78. doi: 10.1152/jappl.1991.70.5.2268.
Four groups of twin sheep fetuses were catheterized at 121 days of gestational age and intravenously infused with saline, 0.75 mg.kg-1.h-1 cortisol for 60 h, five intermittent bolus injections of 5 micrograms/kg thyrotropin-releasing hormone (TRH) at 12-h intervals, or both hormones before delivery at 128 days. At birth, the lambs were randomized to receive surfactant or no treatment. Surfactant treatment improved lung function of all the groups. Corticosteroids alone and in combination with TRH improved compliance and gas exchange as well as pressure-volume curves. Corticosteroids alone dramatically decreased the recovery of intravenously administered radiolabeled albumin in the lung tissue and air space and improved the pulmonary response to surfactant treatment. There were no additional effects of TRH when given with corticosteroids on lung function or albumin leak. There were no changes in alveolar surfactant-saturated phosphatidylcholine pool sizes after any hormone treatment. The single significant effect of combined corticosteroid and TRH treatment was a fivefold increase in surfactant protein A in alveolar lavage fluid relative to all other groups.
四组双胎绵羊胎儿在妊娠121天时进行插管，并静脉输注生理盐水、0.75毫克·千克⁻¹·小时⁻¹的皮质醇持续60小时、每隔12小时进行五次5微克/千克促甲状腺激素释放激素（TRH）的间歇性推注，或在128天分娩前同时输注这两种激素。出生时，将羔羊随机分组接受表面活性剂治疗或不治疗。表面活性剂治疗改善了所有组的肺功能。单独使用皮质类固醇以及与TRH联合使用均可改善顺应性、气体交换以及压力-容积曲线。单独使用皮质类固醇显著降低了肺组织和肺泡腔内静脉注射放射性标记白蛋白的回收率，并改善了肺对表面活性剂治疗的反应。TRH与皮质类固醇联合使用时对肺功能或白蛋白渗漏没有额外影响。任何激素治疗后肺泡表面活性物质饱和磷脂酰胆碱池大小均无变化。皮质类固醇和TRH联合治疗的唯一显著效果是肺泡灌洗液中表面活性蛋白A相对于所有其他组增加了五倍。
