ION CHANNELS IN MUSCLE

将采用多学科方法确定分布情况 研究骨骼肌中离子通道的机制， 控制和维护这些渠道分布。 密度 沿着沿着的通道的长度将用新的 电生理学方法。 通道的合成部位 将用原位杂交和免疫细胞化学测定。 这些电子和组织学的增强空间分辨率 技术揭示了离子通道的复杂排序。 离子 通道是特别重要的调节兴奋性， 神经元和骨骼肌。 如何控制合成和 通道和其他膜蛋白的定位是通过 这是所有细胞的基本问题。 电压门控性钠离子通道的分布和单通道特性 通道将用松膜片电压钳和紧膜片电压钳进行研究。 膜片钳与离子电泳相结合的新技术 将用于发现钠通道的共定位程度， 乙酰胆碱受体 钠离子通道的不同分布 快肌和慢肌可能提示这些通道的功能作用 分布。 钾通道和氯通道分布 将使用相同的技术进行研究，因为有证据表明， 这些也不均匀地分布在肌肉中。 的针对性 将这些研究扩展到其他渠道， 在空间上或响应于扰动而一致地调节。 因此，有可能确定一般和具体的规章制度， 对照 渠道分布的控制可以发生在多个 步 由于骨骼肌细胞是多核的， 同一细胞质中的细胞核受到不同的调节。 这将通过原位杂交进行研究，以确定 钠通道和乙酰胆碱mRNA的丰度和位置 受体的 标记抗体和蛇毒素将用于跟踪 这些通道的蛋白质合成。细胞外和细胞内 可能调节通道合成、分配或 将对固定进行测试。 这些研究也将在另一个 多核细胞，鳗鱼电细胞，也分离膜 蛋白质（钠通道、乙酰胆碱受体和钠-钾通道） 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).