ONTOGENY OF GASTRIC HCL SECRETION

胃氧合细胞分泌盐酸是一种高度专门化的 涉及协同促分泌剂-受体的过程 相互作用，2)细胞质激活，3)招募 细胞质膜进入顶端细胞表面，以及4) 高能运输通道的运营。发展中的 系统为研究分子提供了一个独特的机会 作为HCL基础的一系列事件的特点和限制 分泌物。含氧细胞的形态分化 发生得相当快，表明定义的高合成周期 对于分泌器官的特定元素。我们建议 评估分泌物的个体成分的个体发育 器官伴随着超微结构的发展 含氧细胞和输送HCl的能力。的发展。 H+泵酶，H，K-ATPase，将被研究和关联 与细胞内的管状囊合成模式相关联。 比酶活力、总酶量及相对 泵酶的合成速度将被测定。H+ 大豆分离膜组分的转运活性 将对细胞质小管泡进行研究，并与H+、 K+和C_1-在转化膜中的转运 (通过融合)进入顶端细胞表面。含氧尿酸的个体发育 将建立细胞促分泌素-受体活性，并 与细胞内第二信使的出现相比 激活系统以及各种运输工具的能力 小路。膜合成途径的研究进展 细胞分化与分泌周期中的膜流动 将会建立起来。猪含氧细胞内基因表达的分析 差异化将寻求确定具体的阶段 编码信息，如用于H，K-ATPase合成的信息，在 丰度很高。这些研究将提供一个全面的 表面受体表达年表图。 胞内激活剂、运输酵素和离子通道 构成了含氧细胞的完整分泌机制。 特定蛋白质的个体发育表象与转运 路径还将用作识别标记，并有助于 确定它们在盐酸过程中的相对重要性 分泌物。

Secretion of HCl by the gastric oxyntic cell is a highly specialized process involving coordinated 1) secretagogue-receptor interaction, 2) cytoplasmic activation, 3) recruitment of cytoplasmic membranes into the apical cell surface, and 4) operation of highly energetic transport pathways. The developing system offers a unique opportunity to study the molecular features and limitations in the series of events that underlie HCl secretion. Morphological differentiation of the oxyntic cell occurs rather rapidly, indicating defined periods of high synthesis for particular elements of the secretory apparatus. We propose to evaluate the ontogeny of individual components of the secretory apparatus along with the ultrasturctural development of the oxyntic cell and the ability to transport HCl. The development of the H+ pump enzyme, H,K-ATPase, will be studied and correlated with the pattern of tubulovesicle synthesis within the cell. Specific enzyme activity, total enzyme quantity and relative rates of synthesis of the pump enzyme will be determined. H+ transport activity of isolated membrane fractins deriving from cytoplasmic tubulovesicles will be studied and compared with H+, K+ and C1- transport with membranes that have been transformed (by fusion) into the apical cell surface. The ontogeny of oxyntic cell secretagogue-receptor activity will be established and compared with the appearance of intracellular second messenger activating systems as well as the capacity of the various transport pathways. Pathways for membrane synthesis during cytodifferentiation and membrane flow during the secretory cycle will be established. Analysis of mRNA durig oxyntic cell differentiation will seek to identify stages where specifically coded messages, such as that for H,K-ATPase synthesis, are in high abundance. These studies will provide a comprehensive picture of the chronology for expression of surface receptors. intracellular activators, transport enxymes, and ion channels that constitute the integrated secretory machinery of the oxyntic cell. The ontogenic appearance of specific proteins and transport pathways will also serve as identifying markers and help to establish their relative importance in the process of HCl secretion.