FETAL GASTRIC EPITHELIAL CELLULAR DEVELOPMENT

这项提议验证了胎儿胃上皮细胞 发育严重依赖于营养的管腔作用， 羊水中存在的物质。 初步研究表明，当 在妊娠晚期， 在胎兔体内通过食管结扎， 发生胃的形态和功能发育。 体外羊膜 液体对培养的胎儿胃上皮细胞具有营养作用。 的 该项目的具体目标是：1）检查已知的 羊水中发现的营养剂对胎儿胃发育的影响 2）检查在体内发现的已知营养剂的作用， 羊水对胎胃上皮细胞体外生长的影响; 和3）用免疫荧光法初步分离羊水中的营养因子， 作为生物测定的体外和体内模型。 胃发育 上皮细胞将通过光和电子测量进行形态学评估 显微镜检查和G细胞免疫反应染色。 功能 将通过测量胃酸在体内评估发展， 胃蛋白酶分泌和血清胃泌素水平。 潜在重要营养 要研究的因素包括那些已知的影响新生儿和成人 胃肠道生长，包括：管腔营养素，胃泌素，表皮 生长因子肠胰高血糖素和皮质醇。 亲和层析将 用于选择性地从羊水中去除营养剂， 来评估它们的相对重要性。 此外，羊水将 通过高效液相色谱法和营养 将在体外和体内测试每个级分的活性 生物测定 具有高活性的级分将在一个实施方案中表征。 初步方式。 这项工作具有直接的健康相关的意义， 了解，预防和治疗发育异常的 胃肠道

This proposal tests the hypothesis that fetal gastric epithelial development is critically dependent on the luminal action of trophic substances present in amniotic fluid. Preliminary studies show that when swallowing of amniotic fluid during the third trimester is prevented in vivo by esophageal ligation in the fetal rabbit, marked inhibition of morphologic and functional gastric development occurs. In vitro amniotic fluid has a trophic effect on cultured fetal gastric epithelial cells. The specific aims of this project are to: 1) examine the effects of known trophic agents found in amniotic fluid on the development of fetal gastric epithelium in vivo; 2) examine the effect of known trophic agents found in amniotic fluid on the growth of fetal gastric epithelial cells in vitro; and 3) isolate in a preliminary way trophic factors in amniotic fluid using the in vitro and in vivo models as bioassays. Development of gastric epithelial cells will be assessed morphometrically by light and electron microscopy, and immunoreactive staining for G-cells. Functional development will be assessed in vivo by measurements of gastric acid and pepsin secretion, and serum gastrin levels. Potentially important trophic factors to be studied include those known to affect neonatal and adult gastrointestinal growth, including: luminal nutrients, gastrin, epidermal growth factor, enteroglucagon, and cortisol. Affinity chromatography will be used to selectively remove trophic agents from amniotic fluid in order to assess their relative importance. In addition, amniotic fluid will be fractionated by high performance liquid chromatography and the trophic activity of each fraction will be tested in the in vitro and in vivo bioassays. Fractions with high activity will be characterized in a preliminary way. This work has direct health-related significance in the understanding, prevention, and treatment of developmental anomalies of the gastrointestinal tract.