Schild L, Giebisch G, Green R
Department of Physiology, Yale University School of Medicine, New Haven, CT 06510.
Annu Rev Physiol. 1988;50:97-110. doi: 10.1146/annurev.ph.50.030188.000525.
Our knowledge of chloride transport along the nephron has greatly expanded. Whereas for a long time it was assumed that chloride ions were reabsorbed entirely passively with sodium--the "mendicant" role of chloride, more recent studies suggest that several distinct reabsorptive transport mechanisms operate in parallel. Accordingly, a new model of proximal chloride transport has evolved that includes both active, transcellular as well as passive, intercellular transport pathways. Transcellular chloride reabsorption involves anion exchange mechanisms in both the luminal and peritubular cell membranes, processes that also depend on sodium, hydrogen, and bicarbonate ions. Chloride transport is thus intimately related to sodium and fluid transport as well as to cell acid-base metabolism. Unresolved problems concern the relative magnitude of transcellular and paracellular chloride transport and the details of luminal and basolateral chloride translocation steps.
我们对氯离子沿肾单位转运的认识有了极大的扩展。长期以来，人们一直认为氯离子完全是被动地与钠离子一起重吸收——氯离子的“乞讨者”角色，而最近的研究表明，几种不同的重吸收转运机制并行运作。因此，一种新的近端氯离子转运模型已经形成，该模型包括主动的跨细胞以及被动的细胞间转运途径。跨细胞氯离子重吸收涉及管腔和肾小管周围细胞膜中的阴离子交换机制，这些过程也依赖于钠离子、氢离子和碳酸氢根离子。因此，氯离子转运与钠离子和液体转运以及细胞酸碱代谢密切相关。尚未解决的问题涉及跨细胞和细胞旁氯离子转运的相对大小以及管腔和基底外侧氯离子转运步骤的细节。
