THE HORMONAL CONTROL OF FETAL GROWTH

激素和生长因子刺激体细胞生长的机制 对胎儿的影响知之甚少 大多数已知的激素刺激 产后生长对胎儿生长影响很小或没有影响。 这个项目的总体目标是描绘主要的激素 胎儿躯体生长的刺激物。 特别强调的是， 为了检验生长调节蛋白家族的肽在 人类胎儿的生长 为实现这一目标，将开展 研究旨在：1）评估生长调节素和其他生长因子的作用 刺激体外培养的胎儿细胞的生长。 这将是 通过研究血清成分、细胞外 基质、来自胎儿细胞和组织的条件培养基以及纯化的人 生长调节素C 2)确定其来源和化学性质 胎儿合成的生长调节素。 具体来说，我们将尝试 确定在胚胎生命的早期生长调节素-C是如何产生的， 由所有类型的胚胎细胞产生。 我们还将进行研究， 表征当分离的mRNA在体外翻译时产生的生长调节蛋白。 3)评估胎儿血清中生长调节素-C的生理控制， 新生儿和母亲妊娠期间。 这将通过 胎儿生长调节素C与胎儿大小的关系 健康婴儿和胎儿生长异常的婴儿。 我们也会做 在胎儿和年轻的实验动物中进行研究，以确定生长是否 激素和生长激素样肽在维持 生长调节素

The mechanisms by which hormones and growth factors stimulate the somatic growth of the fetus are poorly understood. Most of the hormones known to stimulate post-natal growth have been shown to exert little or no effect on fetal growth. The overall goal of this project is to delineate the primary hormonal stimulators of fetal somatic growth. Particular emphasis is placed on efforts to test the hypothesis that the somatomedin family of peptides are important in the growth of the human fetus. This objective will be pursued by carrying out studies designed to: 1) Assess the role of somatomedin and other growth factors in the stimulation of growth in vitro of cultured fetal cells. This will be achieved by study of the stimulatory effects of serum components, extracellular matrices, conditioned media from fetal cells and tissues, and purified human somatomedin-C. 2) Determine the site of origin and the chemical nature of somatomedin synthesized by the fetus. Specifically, we will attempt to determine how early in embryonic life somatomedin-C is produced and whether it is produced by all embryonic cell types. We also will perform studies to characterize the somatomedin produced when isolated mRNA is translated in vitro. 3) Assess the physiological control of somatomedin-C in serum from fetuses and newborns and during gestation in mothers. This will be accomplished by determining the relationship of cord serum somatomedin-C with fetal size in healthy infants and infants with abnormalities of fetal growth. We also will do studies in fetuses and young experimental animals to determine whether growth hormone and growth hormone-like peptides are important in maintenance of somatomedin.