DIFFERENTIATION OF ENDOCRINE PANCREAS

胰腺由外分泌组织和内分泌细胞组成 形成了朗格兰群岛 尽管通常 同意胰腺细胞来自内胚层， 关于细胞来源的问题再次被提出 当发现一些内分泌细胞表达 儿茶酚胺酶，一种典型的神经元特性。 本研究 建议我们将测试的假设，表达的 儿茶酚胺酶不是内分泌细胞的反映 它们的起源地，而是生物化学成熟的一个阶段， 胰腺内分泌细胞 我们还将寻求确定B） 内分泌系统中是否出现了儿茶酚胺酶 胰腺的细胞是预先确定的，或者如果它受到胰腺细胞的影响， c）胰腺细胞是否来源于 共同的或单独的前体，并且如果 各种内分泌细胞类型表达儿茶酚胺酶 在发展过程中。 我们还将检验以下假设： 内分泌细胞含有儿茶酚胺酶，是一种 前体人口，能够增殖和增加 胰岛组织的数量。 分化的标准将是免疫组织化学 用抗胰腺激素抗体标记胰岛细胞 和儿茶酚胺酶。 技术设计标记两个 同一细胞中的抗原将用于细胞谱系 分析. 器官型和细胞培养将用于分析 环境在TH和肽调节中的作用 激素表达 最后，假设胰岛生长是 由含有TH的肽细胞增殖产生的肽将 在突变肥胖小鼠中进行测试， 胰岛和转基因小鼠的B细胞肿瘤。

The pancreas is formed by exocrine tissue and by endocrine cells which form the islets of Langherans. Although it is generally agreed that pancreatic cells are derived from the endoderm, questions concerning the origin of the cells were again raised when it was discovered that some endocrine cells express catecholamine enzymes, a typical neuronal trait. In this research proposal we will test the hypothesis that the expression of catecholamine enzymes by endocrine cells in not a reflection of their site of origin but of a stage in the biochemical maturation of pancreatic endocrine cells. We will also seek to determine b) whether the appearance of catecholamine enzymes in endocrine cells of the pancreas is predetermined or if it is influenced by the environment and c) whether pancreatic cells originate from common or separate precursors and if the precursors for the various endocrine cell types express catecholamine enzymes during development. We will also test the hypothesis that endocrine cells containing catecholamine enzyme, being a precursor population, are able to proliferate and increase the amount of islet tissue. The criteria of differentiation will be the immunohistochemical labeling of islet cells with antibodies against pancreatic hormones and catecholamine enzymes. Techniques devised to label two antigens in the same cell will be employed for the cell lineage analysis. Organotypic and cell culture will be used to analyze the role of the environment in the regulation of TH and peptide hormones expression. Finally, the hypothesis that islet growth is produced by proliferation of the peptide cells containing TH will be tested in mutant obese mice, animals that develop hyperplastic islets, and in B-cell tumors of transgenic mice.