ION CHANNELS IN MUSCLE

将使用多学科方法来确定分布情况 骨骼肌中离子通道的研究，以研究产生， 控制和维护这些渠道分布。密度 沿单元格长度的通道的数量将用新的 电生理学方法。经络合成的部位 将通过原位杂交和免疫细胞化学进行检测。 增强的电学和组织学的空间分辨率 技术揭示了离子通道的复杂有序。离子 通道是兴奋性的特别重要的调节因素。 神经元和骨骼肌。如何控制合成和控制 通道和其他膜蛋白的定位完成了 对所有细胞来说都是一个基本问题。 电压门控钠离子的分布和单通道特性 将研究具有松散贴片和紧密贴片电压钳位的通道。 一种结合膜片电压钳和离子导入的新技术 将用于确定钠通道的共局域化程度和 乙酰胆碱受体。体内钠离子通道的不同分布 快肌和慢肌可能暗示了这些通道的功能作用 分配。钾通道和氯离子通道的分布 将使用相同的技术进行研究，因为有证据表明 它们在肌肉中的分布也不均匀。目标的针对性 将这些研究扩展到其他渠道是因为这些渠道不是 在空间上或在对扰动的反应中一致地进行调节。 因此，有可能同时确定一般的和具体的监管 控制。 渠道分配的控制可以发生在多个 台阶。由于骨骼肌细胞是多核的，所以有可能 同一细胞质内的细胞核受到不同的调控。 这将通过原位杂交进行研究，以确定 钠通道和乙酰胆碱信使核糖核酸的丰度和定位 受体。将使用标记的抗体和蛇毒进行追踪 这些通道的蛋白质合成。胞外和胞内 可能调节渠道合成、分配或 将进行固定化测试。这些研究还将进行另一项研究 多核细胞，也就是鳗鱼的电细胞，它也隔膜 蛋白质(钠通道、乙酰胆碱受体和钠-钾 泵)。

A multidisciplinary approach will be used to determine the distribution of ion channels in skeletal muscle ad to study mechanisms for creating, controlling, and maintaining these channel distributions. The density of channels along the length of the cell will be determined with new electrophysiological methods. The site of synthesis of the channels will be determined with in situ hybridization and immunocytochemistry. The enhanced spatial resolution of these electrical and histological techniques is revealing a complex ordering of ion channels. Ion channels are particularly important regulators of excitability in neurons and skeletal muscle. How the control of synthesis and localization of channels and other membrane proteins is accomplished is a fundamental question for all cells. The distribution and single channel properties of voltage-gated sodium channels will be studied with loose patch and tight patch voltage clamp. A new technique which combines both patch voltage clamp and ionophoresis will be used to find the degree of colocalization of sodium channels and acetylcholine receptors. Different distributions of sodium channels in fast and slow muscle may suggest functional roles for these channel distributions. Potassium channel and chloride channel distributions will be studied with the same techniques since there is evidence that these too are nonuniformly distributed in muscle. The pertinence of extending these studies to other channels is that the channels are not regulated in unison either spatially or in response to perturbations. thus it may be possible to identify both general and specific regulatory controls. The control of channel distribution could occur at any of a number of steps. Since skeletal muscle cells are multinucleated, it is possible that nuclei within the same cytoplasm are differentially regulated. This will be studied with in situ hybridization to determine the abundance and location of mRNA for the sodium channel and acetylcholine receptor. Labeled antibodies and snake toxin will be used to follow protein synthesis of these channels. Extracellular and intracellular factors that may regulate channel synthesis, distribution, or immobilization will be tested. These studies will also be done another multinucleated cell, the eel electrocyte, which also segregates membrane proteins (sodium channels, acetylcholine receptors, and sodium-potassium pumps).