FUNCTIONAL DEVELOPMENT OF THE SALIVARY GLANDS

这个项目的总体目标是描述出生后的 体液分泌机制或途径的研究进展 唾液腺中的电解质。我们建议使用一种制剂 1日龄、7日龄、14日龄、21日龄颌下腺细胞散在分布 大鼠在新的资助期内调查这几个方面 路径。在成熟的腺体中，现在已知它涉及到激活 离子传输系统，这导致Na和Na的跨腺泡运动 CL和由此产生的渗透梯度对水的影响。其他证据 表明对唾液腺的刺激增强，就像在各种 其他组织，膜磷脂的周转，导致 作为细胞信使的产物的形成。尽管完全相同的 分泌反应的这两个组成部分之间的关系不是 完全理解，有提示性的证据表明它们通过 细胞内钙的变化。人们对它的外观知之甚少 唾液腺中这种复杂的分泌反应的不同成分 发展。因此，我们建议进行以下调查：1) 单价离子(钠、钾、氯)的跨膜通量 同位素示踪剂。这些离子的吸收和流出将在 没有和存在分泌剂、转运抑制剂和 特定的通道阻滞剂。动力学属性(即，时间进程， 速率、半最大值等)和外部离子的需求 每个流量将被调查；2)刺激诱导的周转 磷脂。肌醇形成和分解的时间进程 磷酸盐、二酰甘油和花生四烯酸将由 放射性标记分子的层析分离；3) 以上2)中确定的产物对细胞内钙离子释放的影响 储存和外在环境对钙离子动员的影响。两者都有 将使用同位素示踪剂(45Ca)和Fura-2的荧光光谱 为了这个目的。这两种钙离子运动对心肌细胞内钙离子浓度的影响 还将通过测量离子来研究单价离子的传输 在存在钙离子通道的情况下，上述1)所示的(同位素)通量 阻滞剂和将其捕获在细胞储存库中的物质(即TMB-8)。这个 这些研究的结果将表明复合体是否存储反应 在出生后发育的所有阶段运行，以及是否所有其 在此期间，组成要素同时发挥作用。

The overall objective of this project is to characterize the postnatal development of the mechanism or pathway underlying the secretion of fluid and electrolytes in salivary glands. We propose to use a preparation of dispersed cells from the submandibular gland of 1, 7, 14 and 21 day old rats to investigate in the new grant period several aspects of this pathway. In mature glands, it is now known to involve the activation of ion transport systems, which results in the transacinar movement of Na and Cl and, by the resulting osmotic gradient, of water. Other evidence indicates that stimulation of salivary glands enhances, as in a variety of other tissues, the turnover of membrane phospholipids, leading to the formation of products which act as cellular messengers. Although the exact relationship between these two components of the secretory response is not fully understood, there is suggestive evidence that they are linked through changes in cell calcium. Little is known about the appearance of the various components of this complex secretory response during salivary gland development. We propose to investigate, therefore, the following: 1) transmembrane fluxes of monovalent ions (Na, K, C1) with the aid of isotopic tracers. Uptake and efflux of these ions will be measured in the absence and in the presence of secretagogues, transport inhibitors and specific channel blockers. The kinetic properties (i.e., time courses, rates, half maximal values, etc.) and the external ionic requirements of each flux will be investigated; 2) stimulation-induced turnover of phospholipids. The time course of formation and breakdown of inositol phosphates, diacylglycerol and arachidonic acid will be investigated by chromatographic separation of radiolabeled molecules; 3) the effects of the products identified in 2) above on the release of Ca++ from intracellular stores and on Ca++ mobilization from the external environment. Both isotopic tracers (45 Ca) and the spectrofluorimetry of fura-2 will be used for this purpose. The effects of these two types of Ca++ movement on monovalent ion transport will also be investigated by measuring the ion (isotope) fluxes indicated in 1) above in the presence of Ca++ channel blockers and of substances which trap it in cell stores (i.e., TMB-8). The results of these studies will indicate whether the complex stores response operates at all stages of postnatal development and whether all its component elements become functional at the same time during this period.