SECOND MESSENGER FUNCTION IN EXOCRINE GLANDS

外分泌腺的第二信使功能

• 批准号: 3220962
• 负责人: THOMAS W HURLEY
• 金额: $ 13.7万
• 依托单位: UNIVERSITY OF MISSOURI-COLUMBIA
• 依托单位国家: 美国
• 财政年份: 1985
• 资助国家: 美国
• 起止时间: 1985-09-01 至 1990-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3220962
• 关键词: 3'5' cyclic nucleotide phosphodiesterase; adenosine triphosphate; adenosinetriphosphatase; adenylate cyclase; alpha adrenergic agent; amylases; autoradiography; beta adrenergic agent; calcium metabolism; cholinergic agents; cyclic AMP; cyclic GMP; cyclic nucleoside monophosphate; cytoplasm; exocrine glands; gel electrophoresis; guanylate cyclase; hormone regulation /control mechanism; ion transport; membrane permeability; messenger RNA; pancreas; peptidyl dipeptidase A; phosphorylation; potassium; protein kinase; radiotracer; secretion; sialate; submandibular gland

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.

唾液腺和胰腺中分泌的机制需要 Ca2+和环状核苷酸，但第二个的精确作用 信使及其胞质浓度的调节仅是 部分理解。 这些研究将评估以下假设 控制第二信使浓度的控制部分由第二次控制 使者自己。 该假设将在比较中进行检验 使用大鼠下颌腺的腺泡制剂和 胰腺作为模型系统的（1）表征动力学和调节性 控制第二信使浓度的酶的特性： 高亲和力CAATPase和Active Ca2+易位，腺苷酸盐和 鸟苷酸环化酶活性和CAMP和CGMP磷酸二酯酶 活动; （2）表征形式的动力学特性 那些由Ca2+ - 钙化蛋白复合物调节的酶。 第二个目标 这些研究是确定第二使者对激酶的影响 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 检测并表征调节的激酶的磷酸化底物 由破裂的腺泡细胞中的第二个使者。 在其他研究中， 功能功能的腺泡制剂将与p32孵育以标记 然后，细胞内ATP暴露于胆碱能，α和β肾上腺素能或 肽能代理。 分泌响应（就k+的释放而言， 淀粉酶或从分泌的糖蛋白中释放的唾液酸）将是 此后在不同时间测量并与蛋白质变化相关 磷酸化。 在平行研究中，Acini将暴露于 在抑制，增强和/或模仿的代理的存在下进行的秘密 第二使者的影响是为了将变化的变化相关联 第二信使依赖性磷酸化，分泌物变化 回复。 这些研究将产生有关 定义明确的模型外分泌中刺激 - 分泌耦合的机理 系统并将提供有关比较生理学的新见解 涉及各种疾病的分泌系统。 另外这些 研究对于定义调节正常的因素很重要 唾液腺功能，因此对于维持很重要 在口腔中健康的软和矿化组织。