SECOND MESSENGER FUNCTION IN EXOCRINE GLANDS

外分泌腺的第二信使功能

• 批准号: 3220970
• 负责人: THOMAS W HURLEY
• 金额: $ 16.54万
• 依托单位: UNIVERSITY OF MISSOURI-COLUMBIA
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-09-30 至 1994-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3220970
• 关键词: acinar cell; adenylate cyclase; calcium metabolism; calcium transporting ATPase; calmodulin; cell membrane; chemical structure function; chlorine; cholecystokinin; cholinergic receptors; cyclic nucleoside monophosphate; endoplasmic reticulum; exocrine glands; guanylate cyclase; hormone regulation /control mechanism; hydrogen; laboratory rat; magnesium; newborn animals; pancreas; phosphorylation; potassium; second messengers; secretion; sodium; submandibular gland; weanling animal

The mechanism of secretion in salivary glands and the pancreas requires Ca2+ and the cyclic nucleotides, but the precise roles of those second messengers and the regulation of their cytosolic concentrations are only partially understood. These studies will evaluate the hypothesis that control of second messenger concentration effected, in part, by the second messengers themselves. This hypothesis will be tested in comparative studies using acinar preparations of the rat submandibular gland and pancreas as model systems to (1) characterize the kinetic and regulatory properties of the enzymes that control second messenger concentration: high affinity CaATPase and active Ca2+ translocation, adenylate and guanylate cyclase activities and cAMP and cGMP phosphodiesterase activities; and (2) characterize the kinetic properties of the forms of those enzymes regulated by the Ca2+-calmodulin complex. A second goal of these studies is to determine the effects of second messengers on kinase activities in exocrine glands and to evaluate the hypothesis that secretion depends on second messenger-regulated protein phosphorylation. Polyacrylamide gel electrophoresis and autoradiography will be used to detect and characterize the phosphorylated substrates of kinases regulated by the second messengers in broken acinar cells. In other studies, functioning acinar preparations will be incubated with P32 to label intracellular ATP then exposed to cholinergic, Alpha and Beta adrenergic or peptidergic agents. Secretory responses (in terms of release of K+, of amylase or as sialic acid liberated from secreted glycoproteins) will be measured at various times thereafter and correlated with changes in protein phosphorylation. In parallel studies, acini will be exposed to secretagogues in the presence of agents which inhibit, augment and/or mimic the effects of the second messengers in order to correlate changes in second messenger-dependent phosphorylation with changes in secretory response. These studies will yield new information concerning the mechanism of stimulus-secretion coupling in well-defined model exocrine systems and will provide new insights regarding the comparative physiology of secretory systems involved in a variety of diseases. In addition these studies will be important in defining the factors that regulate normal salivary gland function and therefore are important for the maintenance of healthy soft and mineralized tissue in the oral cavity.

唾液腺和胰腺的分泌机制需要 Ca2+ 和环核苷酸，但第二个的确切作用 信使及其胞质浓度的调节只是 部分理解。 这些研究将评估以下假设： 第二信使浓度的控制部分受到第二信使的影响 使者本身。 该假设将在比较中得到检验 使用大鼠颌下腺腺泡制剂进行的研究 胰腺作为模型系统（1）表征动力学和调节 控制第二信使浓度的酶的特性： 高亲和力 CaATPase 和活性 Ca2+ 易位、腺苷酸和 鸟苷酸环化酶活性以及 cAMP 和 cGMP 磷酸二酯酶 活动; (2) 表征形式的动力学特性 这些酶受 Ca2+-钙调蛋白复合物调节。 第二个目标是 这些研究是为了确定第二信使对激酶的影响 外分泌腺的活动并评估分泌的假设 取决于第二信使调节的蛋白质磷酸化。 聚丙烯酰胺凝胶电泳和放射自显影将用于 检测并表征所调节激酶的磷酸化底物 由破碎的腺泡细胞中的第二信使产生。 在其他研究中， 功能性腺泡制剂将与 P32 一起孵育以进行标记 然后将细胞内 ATP 暴露于胆碱能、α 和 β 肾上腺素或 肽能药物。 分泌反应（就 K+ 的释放而言， 淀粉酶或从分泌的糖蛋白中释放唾液酸） 此后在不同时间进行测量并与蛋白质的变化相关 磷酸化。 在平行研究中，腺泡将暴露于 存在抑制、增强和/或模拟的促分泌剂 第二信使的影响，以便将变化联系起来 第二信使依赖性磷酸化与分泌变化 回复。 这些研究将产生有关 明确的外分泌模型中刺激-分泌耦合的机制 系统并将提供有关比较生理学的新见解 分泌系统与多种疾病有关。 另外这些 研究对于确定调节正常的因素非常重要 唾液腺功能，因此对于维持 口腔中健康的软组织和矿化组织。