Sadiq H F, Devaskar U P
Biochem Biophys Res Commun. 1984 Feb 29;119(1):408-14. doi: 10.1016/0006-291x(84)91667-x.
Experimental evidence in animals and humans suggest that glucocorticoids enhance fetal pulmonary maturation. Mechanisms of glucocorticoid effects remain unclear; but apparently include up regulation of fetal pulmonary insulin and beta-adrenergic receptors. A role of Epidermal Growth Factor (EGF) in fetal lung maturation through plasma membrane bound receptors has been recently proposed. Betamethasone, 0.085 mg/kg, was administered on 25th and 26th day of gestation to the rabbit doe. Fetal pulmonary EGF receptor characteristics in male or female fetuses were studied on the 27th day of pregnancy. The percent specific binding of 125-I-EGF to lung plasma membranes (LPM) and the number of receptor sites per mg of LPM protein or DNA content were significantly higher in the glucocorticoid treated female as well as male fetuses when compared to the control pups, with no difference in the Kd. Presence of high affinity receptors for EGF and their up regulation by glucocorticoids support the hypothesis that EGF plays an important role in fetal lung maturation and that some of the beneficial effects of glucocorticoids in decreasing the incidence of HMD may be mediated through its interaction with EGF.
动物和人类的实验证据表明，糖皮质激素可促进胎儿肺成熟。糖皮质激素作用的机制尚不清楚；但显然包括胎儿肺胰岛素和β-肾上腺素能受体的上调。最近有人提出，表皮生长因子（EGF）通过质膜结合受体在胎儿肺成熟中发挥作用。在妊娠第25天和第26天，给兔母兔注射0.085mg/kg的倍他米松。在妊娠第27天，研究了雄性或雌性胎儿的胎儿肺EGF受体特征。与对照幼崽相比，糖皮质激素处理的雌性和雄性胎儿中，125-I-EGF与肺质膜（LPM）的特异性结合百分比以及每毫克LPM蛋白或DNA含量的受体位点数量显著更高，Kd无差异。EGF高亲和力受体的存在及其被糖皮质激素上调支持了这样的假设，即EGF在胎儿肺成熟中起重要作用，糖皮质激素在降低HMD发生率方面的一些有益作用可能是通过其与EGF的相互作用介导的。
