钠/氢交换体在肾脏酸碱平衡调节中的作用
Na+/H+ exchangers in renal regulation of acid-base balance.
作者信息
Bobulescu I Alexandru, Moe Orson W
机构信息
Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.
出版信息
Semin Nephrol. 2006 Sep;26(5):334-44. doi: 10.1016/j.semnephrol.2006.07.001.
The kidney plays key roles in extracellular fluid pH homeostasis by reclaiming bicarbonate (HCO(3)(-)) filtered at the glomerulus and generating the consumed HCO(3)(-) by secreting protons (H(+)) into the urine (renal acidification). Sodium-proton exchangers (NHEs) are ubiquitous transmembrane proteins mediating the countertransport of Na(+) and H(+) across lipid bilayers. In mammals, NHEs participate in the regulation of cell pH, volume, and intracellular sodium concentration, as well as in transepithelial ion transport. Five of the 10 isoforms (NHE1-4 and NHE8) are expressed at the plasma membrane of renal epithelial cells. The best-studied isoform for acid-base homeostasis is NHE3, which mediates both HCO(3)(-) absorption and H(+) excretion in the renal tubule. This article reviews some important aspects of NHEs in the kidney, with special emphasis on the role of renal NHE3 in the maintenance of acid-base balance.
肾脏在细胞外液pH值稳态中发挥关键作用，通过重吸收肾小球滤过的碳酸氢根（HCO₃⁻）并向尿液中分泌质子（H⁺）以生成消耗的HCO₃⁻（肾脏酸化）。钠-质子交换体（NHEs）是普遍存在的跨膜蛋白，介导Na⁺和H⁺跨脂质双层的反向转运。在哺乳动物中，NHEs参与细胞pH值、体积和细胞内钠浓度的调节，以及跨上皮离子转运。10种异构体中的5种（NHE1-4和NHE8）在肾上皮细胞质膜上表达。对酸碱平衡研究最深入的异构体是NHE3，它介导肾小管中HCO₃⁻的吸收和H⁺的排泄。本文综述了NHEs在肾脏中的一些重要方面，特别强调了肾NHE3在维持酸碱平衡中的作用。
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