Mulay S, Browne C A, Varma D R, Solomon S
Fed Proc. 1980 Feb;39(2):261-5.
Fetal growth retardation due to maternal malnutrition is widespread especially in the Third World. Little is known about the mechanisms that regulate the growth of the fetus and placenta during protein malnutrition. It is known that the placental size and levels of circulating placental hormones such as human chorionic gonadotrophins (hCG), human placental lactogen (hPL), and estrogens are affected by the nutritional status of the mother. There is suggestive evidence that during malnutrition, hPL may increase lipolysis and exert a glucose sparing effect in the mother, thereby promoting glucose availability to the fetus. We have studied the influence of dietary protein deficiency on the binding of dexamethasone to the specific cytosol receptors in adult and fetal tissues. A low protein diet in adult male rats is associated with a decrease in dexamethasone binding to liver cytosol receptors. On the other hand, protein deprivation in pregnant female rats leads to an increase in dexamethasone binding to liver cytosol receptors of both the mother and fetus. However, the influences of maternal protein deprivation on dexamethasone receptors in the fetal liver and lungs are not similar. At 21 days gestation the binding of dexamethasone to fetal lung receptors of protein-deficient mothers is lower than that in the controls. These differences at a critical time in the fetal lung development indicate that a fall in receptors for dexamethasone may lead to impaired phospholipid synthesis in fetuses of protein-deficient mothers and point to the importance of nutritional factors in the biochemistry of fetal development.
由于母亲营养不良导致的胎儿生长迟缓现象普遍存在,尤其是在第三世界。关于蛋白质营养不良期间调节胎儿和胎盘生长的机制,人们了解甚少。已知胎盘大小以及循环胎盘激素(如人绒毛膜促性腺激素(hCG)、人胎盘催乳素(hPL)和雌激素)的水平会受到母亲营养状况的影响。有迹象表明,在营养不良期间,hPL可能会增加母亲体内的脂肪分解并发挥节约葡萄糖的作用,从而提高胎儿可获得的葡萄糖量。我们研究了饮食蛋白质缺乏对成年和胎儿组织中地塞米松与特定胞质受体结合的影响。成年雄性大鼠的低蛋白饮食与地塞米松与肝细胞质受体的结合减少有关。另一方面,怀孕雌性大鼠的蛋白质缺乏会导致母亲和胎儿肝脏细胞质受体的地塞米松结合增加。然而,母亲蛋白质缺乏对胎儿肝脏和肺部地塞米松受体的影响并不相同。在妊娠21天时,蛋白质缺乏母亲的胎儿肺受体与地塞米松的结合低于对照组。胎儿肺发育关键时期的这些差异表明,地塞米松受体的减少可能导致蛋白质缺乏母亲的胎儿磷脂合成受损,并指出营养因素在胎儿发育生物化学中的重要性。