MOLECULAR MECHANISMS OF ION TRANSPORT BY THE SMG

描述(改编自《调查员摘要》)：的总体目标 这一提议是为了了解流体和 有病灶的颌下腺(SMG)的电解质分泌 在分泌物的导管成分上。中的矢量离子输运 唾液上皮细胞需要特定离子的极化表达 传送者。此外，离子输运的调节和定位 管道系统的特征一直很差。一个综合性的细胞 已经提出了生理、生化和分子方法来测试 模型，这是这一提议的工作假设。的目标是 建议是：(1)研究新发现的CFTR的作用和 ENAC对腺泡腔膜HCO3-、Cl-和Na外流的影响 细胞；(2)检查“拉-推”模型与流明的平行 氯离子/HCO3交换在介导转导氯离子转运中的作用；(3)测定 HCO_3进入基底外侧膜的主要机制 K-HCO3在Lm中的外流；(4)评价 Enac和cftr调节两个通道的活性，从而调节氯化钠。 吸收和偶联KHCO3分泌；以及(5)跟踪活性 在整体模式的背景下，对个别运输/道路进行评估。 这项研究将使用该小组以前采用方法来研究离子 胰腺细胞中的转运蛋白以及最近建立的技术 目的：研究颌下腺导管内的离子转运体。通过使用 电生理学研究(膜片钳测量)、荧光 测量(使用特定染料测定胞浆pH和 各种离子的浓度)、细胞体积测量以及 免疫细胞化学，特定离子的功能定位 SMG导管细胞中的转运蛋白已被提出。

DESCRIPTION (Adapted from the investigator's Abstract): The overall goal of this proposal is to understand the molecular mechanism underlying fluid and electrolyte secretion by the submandibular salivary gland (SMG) with a focus on the ductal component of the secretion. Vectorial ion transport in salivary epithelial cells requires polarized expression of specific ion transporters. Further, the regulation and localization of the ion transport systems of the duct have been poorly characterized. A comprehensive cell physiological, biochemical, and molecular approach has been proposed to test the model, which is the working hypothesis of this proposal. The aims of the proposal are to: (1) study the role of the newly discovered CFTR and ENaC on HCO3-, Cl- and Na+ efflux in the luminal membrane (LM) of acinar cells.; (2) to examine the "pull-push" model in parallel with a luminal Cl-/HCO3 exchange in mediating transductal Cl-transport; (3) to determine the major mechanism of HCO3 influx in the basolateral membrane (BLM) and K+-HCO3 efflux in the LM; (4) to evaluate whether direct interaction between ENaC and CFTR regulates the activity of the two channels and thereby NaCl absorption and the coupled KHCO3 secretion; and (5) to follow the activity of the individual transport/pathways in the context of the overall model. The study will use methodology previously applied by this group to study ion transporters in pancreatic cells and also more recent techniques established to study the ion transporters in the submandibular gland duct. By using electrophysiological studies (patch clamp measurements), fluorescence measurement (using specific dyes to determine cytosolic pH and the concentrations of various ions), cell volume measurements, and immunocytochemistry, the functional localization of the specific ion transporters in the SMG ductal cell has been proposed.