ROLE OF PLACENTAL LATOGEN IN FETAL DEVELOPMENT

这个实验室最近的研究表明， 胎盘催乳素的代谢和促生长作用 胎儿组织通过荷尔蒙与一种 独特的磷脂酰胆碱受体。我们现在提议调查 体外培养人胎儿组织中PL受体的调节 在活体绵羊胎肝内。各种激素和激素的作用 生长因子在调节人PL受体中的作用 放射性标记人磷脂酶(HPL)结合研究中的检测 对人胎儿成肌细胞和肝细胞的作用。这些研究将 研究胰岛素，胰岛素样生长因子的影响， HPL、甲状腺素、氢化可的松和性激素对数字的影响 以及培养细胞中HPL受体的亲和力。的作用 在体内调节PL受体的营养因素将是 放射性标记绵羊磷脂酶与磷脂酶结合的研究 绵羊胎肝微粒体。这些研究将考察 母体禁食和胎儿高血糖对围产儿血糖的影响 胎儿OPL受体的数量和亲和力。的影响 孕妇禁食或胎儿高血糖对胎儿OPL受体的影响 将与血浆中葡萄糖浓度的变化有关， 胰岛素、胰岛素样生长因子I和II、OPL、OGH和OPRL 胎羊与胎肝DNA和糖原变化的关系 内容。激素和营养对大鼠磷脂酶受体的影响 体外培养的人胎儿组织和体内的羊胎肝组织将被 比较对胎儿表皮生长因子受体的影响。 胎儿PL受体体外调控的研究进展 在体内应该提供对控制因素的洞察力 PL在胎儿中的作用。由于磷脂在中国有促进生长的作用 胎儿组织，这些研究应该有助于我们理解 荷尔蒙对胎儿生长的控制。对影响的研究 孕妇禁食胎儿PL受体可能有助于阐明 产妇禁食和营养不良的发生机制 胎儿发育迟缓。反过来说，研究的影响 胎儿高血糖(和伴随的胎儿高胰岛素血症) 胎儿PL受体可能为研究其发病机制提供新的视角 妊娠合并母婴巨大儿的发生率 糖尿病。

Recent studies from this laboratory have demonstrated that the metabolic and somatotropic effects of placental lactogen (PL) in fetal tissues are mediated through binding of the hormone to a distinct and unique PL receptor. We now propose to investigate the regulation of the PL receptor in human fetal tissues in vitro and in ovine fetal liver in vivo. The roles of various hormones and growth factors in the regulation of the human PL receptor will be examined in studies of the binding of radiolabeled human PL (hPL) to human fetal myoblasts and hepatocytes. These studies will examine the effects of insulin, the insulin-like growth factors, hPL, thyroxine, hydrocortisone and the sex steroids on the number and affinity of hPL receptors in cultured cells. The role of nutritional factors in the regulation of PL receptors in vivo will be examined in studies of the binding of radiolabeled ovine PL to ovine fetal liver microsomes. These studies will examine the effects of maternal fasting and fetal hyperglycemia on the number and affinity of fetal oPL receptors. The effects of maternal fasting or fetal hyperglycemia on fetal oPL receptors will be related to changes in the plasma concentrations of glucose, insulin, insulin-like growth factors I and II, oPL, oGH and oPRL in the fetal lamb and to changes in fetal hepatic DNA and glycogen content. The hormonal and nutritional effects on PL receptors in human fetal tissues in vitro and in ovine fetal liver in vivo will be compared to effects on fetal epidermal growth factor recetors. These studies of the regulation of the fetal PL receptor in vitro and in vivo should provide insight into the factors which control PL action in the fetus. Since PL has growth-promoting effects in fetal tissues, these studies should contribute to our understanding of the hormonal control of fetal growth. Studies of the effects of maternal fasting on fetal PL receptors may clarify the mechanisms by which maternal fasting and malnutrition give rise to fetal growth retardation. Conversely, studies of the effects of fetal hyperglycemia (and concomitant fetal hyperinsulinemia) on fetal PL receptors may provide new insight into the pathogenesis of fetal macrosomia in pregnancies complicated by maternal diabetes mellitus.