[Sodium and water transport along the nephron].
Kidney is the most important organ to maintain the homeostasis. Glomeruli filtrate water and sodium as much as 150 l/day and 21 Eq/day, however, more than 99% of them reabsorbed along the nephron. Sodium reabsorption is the energy to reabsorb water and regulate electrolyte homeostasis, as the basic mechanism of electrolyte transport was driven by the electrochemical gradient across the cell membrane originated by the Na-K ATPase located in the basolateral membrane. On the apical membrane, there are various kinds of transporters, such as Na-H exchanger, Cl-bicarbonate exchanger, Na-amino acid cotransporter, Na-glucose cotransporter, Na-phosphate cotransporter, Na-Cl cotransporter, Na channels, K channels, and so on. Each segment has specific transporters and specific characteristics to water permeability. As a total, each nephron segment plays artistic roles to regulate water, sodium and other electrolytes transport.
Tabei
Kaoru
K
Division of Nephrology, Department of Integrated Medicine, Omiya Medical Center, Jichi Medical School.
D001692:Biological Transport / Q000502:physiology; D006801:Humans; D009399:Nephrons / Q000502:physiology*; D012964:Sodium / Q000378:metabolism*; D014882:Water-Electrolyte Balance / Q000502:physiology*
D012964:Sodium