Hallman M, Teramo K, Sipinen S, Raivio K
J Perinat Med. 1985;13(1):23-9. doi: 10.1515/jpme.1985.13.1.23.
Beta-sympathomimetic drugs and glucocorticoid agents are given in preterm labor to prevent severe consequences of prematurity. It is unclear whether beta-sympathomimetics accelerate lung maturation, or whether they only tend to delay preterm delivery. We have evaluated the effects of betamethasone and ritodrine in rabbits on alveolar lavage phospholipids in premature rabbits, a mean of 28.7 days from conception. Betamethasone given to 26-day-old fetuses increased the surfactant phospholipids, phosphatidylinositol and disaturated phosphatidylcholine; increased disaturated phosphatidylcholine/sphingomyelin ratio, and phosphatidylinositol (percent of phospholipids), as compared to untreated littermates, or to saline treated controls. A low dose of ritodrine given to the pregnant doe, and a high dose given at premature birth had no detectable effects on alveolar lavage phospholipids. However, a high dose of ritodrine given one day before the delivery to the fetus and at premature birth decreased the disaturated phosphatidylcholine/sphingomyelin ratio and phosphatidylinositol in alveolar lavage. While glucocorticoid administration increases the synthesis and secretion of surfactant phospholipids, a high dose of a betasympathomimetic drug may decrease the surfactant. However, spontaneous premature labor is associated with accelerated lung maturation, and accordingly the present results do not contradict the use of a low dosage of betasympathomimetic drug to delay preterm delivery.
β-拟交感神经药物和糖皮质激素制剂用于早产以预防早产的严重后果。目前尚不清楚β-拟交感神经药物是加速肺成熟，还是仅仅倾向于延迟早产。我们评估了倍他米松和利托君对受孕后平均28.7天的早产兔肺泡灌洗磷脂的影响。与未治疗的同窝仔兔或生理盐水处理的对照组相比，给26日龄胎儿注射倍他米松可增加表面活性物质磷脂、磷脂酰肌醇和二饱和磷脂酰胆碱；增加二饱和磷脂酰胆碱/鞘磷脂比值以及磷脂酰肌醇（占磷脂的百分比）。给怀孕母兔注射低剂量利托君以及在早产时注射高剂量利托君对肺泡灌洗磷脂没有可检测到的影响。然而，在分娩前一天给胎儿注射高剂量利托君以及在早产时注射高剂量利托君会降低肺泡灌洗中的二饱和磷脂酰胆碱/鞘磷脂比值和磷脂酰肌醇。虽然给予糖皮质激素会增加表面活性物质磷脂的合成和分泌，但高剂量的β-拟交感神经药物可能会降低表面活性物质。然而，自发性早产与肺成熟加速有关，因此目前的结果并不与使用低剂量β-拟交感神经药物延迟早产相矛盾。
