Giebisch G H
Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut 06520, USA.
Yale J Biol Med. 1997 Jul-Aug;70(4):311-22.
Potassium channels in the apical and basolateral membranes of tubule cells serve several important functions. They contribute to the generation of the cell-negative potential, mediate volume reductions following cell swelling and play a key role in secretion of potassium in both the thick ascending limb of Henle's loop and principal tubule cells of the initial and cortical collecting tubules. Secretion of potassium occurs via a well-defined class of potassium channels distinguished by their low single channel conductance, mild inward rectification, high sensitivity to inhibition by low pH, millimolar concentrations of ATP, arachidonic acid and PKC, and stimulation by vasopressin and pretreatment with a high potassium diet. Genes encoding several isoforms of this channel have been cloned and the proteins located to the apical membranes of cells lining the thick ascending limb of Henle's loop and the collecting tubules, and progress made concerning their structure-function relationship.
肾小管细胞顶端膜和基底外侧膜中的钾通道具有多种重要功能。它们有助于产生细胞负电位，介导细胞肿胀后的体积减小，并在髓袢升支粗段以及初始和皮质集合小管的主细胞中钾的分泌过程中发挥关键作用。钾的分泌通过一类明确的钾通道进行，这类通道的特点是单通道电导低、轻度内向整流、对低pH、毫摩尔浓度的ATP、花生四烯酸和蛋白激酶C的抑制高度敏感，以及对血管加压素和高钾饮食预处理有刺激作用。编码该通道几种同工型的基因已被克隆，其蛋白质定位于髓袢升支粗段和集合小管内衬细胞的顶端膜，并且在其结构-功能关系方面取得了进展。
