Yokoyama N, Takada S, Uetani Y, Nakamura H
Department of Pediatrics, Kobe University School of Medicine, Japan.
Biol Neonate. 1995;68(1):39-46. doi: 10.1159/000244216.
To determine the effects of maternal administration of dexamethasone (DEX) and thyrotropin-releasing hormone (TRH) on fetal lung maturation, 16 pregnant rats were divided into the following four groups: 20 micrograms/kg TRH twice a day was given intraperitoneally to the TRH group rats, 0.5 mg/kg/day DEX to the DEX group and both DEX and TRH to the DEX + TRH group for 3 consecutive days from gestational day 17. The control rats were given an equivalent volume of saline. The pregnant rats were sacrificed on gestational day 20 and the fetal lungs were removed. The relative amounts of surfactant protein A (SP-A), B (SP-B) and C (SP-C) mRNAs were analyzed by Northern blotting and the total lung disaturated phosphatidylcholine (DSPC) contents were determined using an enzymatic method. The SP-B and -C mRNA and DSPC contents in the DEX and DEX + TRH groups were significantly higher than those in the control group, whereas the SP-A mRNA levels did not differ significantly among the four groups. The SP-B and -C mRNA and DSPC contents in the DEX and DEX + TRH groups did not differ significantly. These findings suggest that TRH has no effects on the regulation of surfactant protein mRNAs or DSPC contents in the fetal rat lung and has no additive effects when combined with DEX.
为确定母体给予地塞米松（DEX）和促甲状腺激素释放激素（TRH）对胎儿肺成熟的影响，将16只孕鼠分为以下四组：从妊娠第17天起，连续3天对TRH组大鼠腹腔注射20微克/千克TRH，每日两次；对DEX组注射0.5毫克/千克/天的DEX；对DEX + TRH组同时注射DEX和TRH。对照组大鼠注射等量生理盐水。在妊娠第20天处死孕鼠并取出胎儿肺。通过Northern印迹法分析表面活性蛋白A（SP-A）、B（SP-B）和C（SP-C）mRNA的相对含量，并用酶法测定肺总不饱和磷脂酰胆碱（DSPC）含量。DEX组和DEX + TRH组的SP-B和-C mRNA以及DSPC含量显著高于对照组，而四组间SP-A mRNA水平无显著差异。DEX组和DEX + TRH组的SP-B和-C mRNA以及DSPC含量无显著差异。这些结果表明TRH对胎鼠肺表面活性蛋白mRNA或DSPC含量的调节无影响，且与DEX联合使用时无相加作用。
