Challenges to potassium metabolism: internal distribution and external balance.
Challenges to potassium metabolism: internal distribution and external balance.
复制标题
钾代谢的挑战：内部分配和外部平衡。
DOI：
10.1007/bf03040914
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发表时间：
2004
影响因子：
2.6
通讯作者：
Giebisch,Gerhard
中科院分区：
文献类型：
--
作者：
Giebisch,Gerhard
一个复杂的泵-泄漏系统，包括主动和被动运输机制，负责钾(K)在细胞内液和胞外液室之间的适当分配。此外，肾脏，以及较小程度的结肠，维持细胞外液中的低K浓度的狭窄范围。早期的肾脏清除研究表明，钾通常由肾小管重吸收和分泌，调节分泌是钾排泄的主要来源。净排钾主要发生在主细胞，而钾吸收主要发生在间质细胞。对单小管、主细胞和嵌入细胞的研究已经明确了K分泌和重吸收的决定因素，包括电化学驱动力、特定载体、ATPase和K通道。最近对肾脏钾通道的性质和分子特性的研究也有助于理解肾脏转运和调节钾排泄的机制。
A complex pump-leak system involving both active and passive transport mechanisms is responsible for the appropriate distribution of potassium (K) between the intra- and extracellular fluid compartments. In addition, the kidneys, and to a lesser extent the colon, safeguard maintenance of the narrow range of low K concentrations in the extracellular fluid. Early renal clearance studies showed that K is normally both reabsorbed and secreted by renal tubules, and that regulated secretion is the major source of K excretion. Net K secretion occurs mainly in principal cells while K absorption takes place in intercalated cells. Studies on single tubules and principal and intercalated cells have defined the determinants of K secretion and reabsorption including the electrochemical driving forces, specific carriers, ATPases, and K channels. Recent studies on the properties and molecular identity of renal K channels have also contributed significantly to understanding the renal mechanisms that transport and regulate K excretion.