REGULATION OF TRANSPORT IN EPITHELIA

上皮细胞运输的调节

基本信息

批准号：
3152874
负责人：
DAVID ERLIJ
金额：
$ 10.82万
依托单位：
SUNY DOWNSTATE MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
1984
资助国家：
美国
起止时间：
1984-04-01 至 1987-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/3152874
关键词：
apical membrane basolateral membrane calcium metabolism cell morphology computer data analysis electrochemistry epithelium hormone regulation /control mechanism ion transport membrane permeability membrane potentials microelectrodes prostaglandins skin

项目摘要

Transepithelial Na+ transport in tight epithelia involves the movement of ions across two separate barriers: the apical and basolateral membranes. We are characterizing the involvement of these membranes in the response to regulatory influences using the frog skin as a model epithelium. An important part of our experiments involves the use of intracellular microelectrodes to determine the current-voltage relationships (IV) of the two barriers. With respect to the apical membrane we are testing whether the relationship between the Na current and the membrane potential is described by the Goldman constant-field equation over a wide variety of circumstances. Conformity with this equation allows the calculation of the conductance, permeability and electromotive force of this barrier. We are using the IV relationship of the basolateral border to attempt to characterize the changes of this border during the action of regulators. Ion selective microelectrodes for Na+ and K+ will be used to examine the dependence of the transport parameters of the two barriers on cytoplasmic ion activity. The measurements of intracellular ion activities will also be used to verify the conclusions reached from measurements of the IV relationship. In addition, the microelectrode data will allow us to determine the conditions in which to use noise analysis to examine the relationship between the electrochemical driving force and the single channel current of the apical border. In addition to studying the better characterized modifiers of ion transport, special attention will be given to the regulation exerted by cell volume and cell Ca2+ activity. We will particularly examine the role of prostaglandin release in the responses to volume changes. Finally, in a different group of experiments we will examine whether Cl- moves across the epithelium through the same cells that transport Na+ or through a different pathway.

transepithialial na+紧密上皮中的运输涉及运动离子横跨两个单独的障碍：顶端和基底外侧膜。我们正在表征这些膜参与对使用青蛙皮肤作为模型上皮的调节影响。一个我们实验的重要部分涉及细胞内的使用微电极以确定该电流 - 电压关系（IV）两个障碍。关于顶膜，我们正在测试是否 NA电流与膜电位之间的关系是高盛恒定场方程描述了各种各样的情况。符合此方程式允许计算该屏障的电导，渗透性和电动力。我们是使用基底外侧边界的IV关系尝试在监管机构的作用过程中表征该边界的变化。 Na+和K+的离子选择性微电极将用于检查两个障碍在细胞质上的传输参数的依赖性离子活性。细胞内离子活性的测量也将可用于验证IV的测量结果得出的结论关系。此外，微电极数据将使我们能够确定使用噪声分析检查的条件电化学驱动力与单个之间的关系顶端边界的通道电流。除了研究更好的离子运输的特征修饰符，将特别注意对细胞体积和细胞Ca2+活性所施加的调节。我们将特别研究前列腺素释放在对音量变化。最后，在不同的实验中，我们将检查cl-是否通过同一细胞穿过上皮移动运输Na+或通过不同的途径。