Cellular model of proximal tubule NaCl and NaHCO3 absorption
نویسندگان
چکیده
منابع مشابه
Contributions of cellular leak pathways to net NaHCO3 and NaCl absorption.
Proton and formic acid permeabilities were measured in the in vivo microperfused rat proximal convoluted tubule by examining the effect on intracellular pH when [H] and/or [formic acid] were rapidly changed in the luminal or peritubular fluids. Apical and basolateral membrane H permeabilities were 0.52 +/- 0.07 and 0.67 +/- 0.18 cm/s, respectively. Using these permeabilities we calculate that p...
متن کاملEssential role of NHE3 in facilitating formate-dependent NaCl absorption in the proximal tubule.
The absorption of NaCl in the proximal tubule is markedly stimulated by formate. This stimulation of NaCl transport is consistent with a cell model involving Cl(-)-formate exchange in parallel with pH-coupled formate recycling due to nonionic diffusion of formic acid or H(+)-formate cotransport. The formate recycling process requires H(+) secretion. Although Na(+)-H(+) exchanger isoform NHE3 ac...
متن کاملFormate-stimulated NaCl absorption in the proximal tubule is independent of the pendrin protein.
A significant fraction of active chloride reabsorption across the apical membrane of the proximal tubule is mediated by a chloride/formate exchange process, whereby intracellular formate drives the transport of chloride into the cell. When chloride/formate exchange operates in parallel with Na(+)/H(+) exchange and H(+)-coupled recycling of formate, the net result is electroneutral NaCl reabsorp...
متن کاملSodium, bicarbonate, and chloride absorption by the proximal tubule.
Proximal tubules are lined with epithelial cells that contain Na-K-ATPase in their basolateral cell membrane. The luminal cell membrane contains transport proteins that couple movement of many solutes to the active transport of sodium. The cells are connected by low-resistance junctional complexes that permit passive movement of solutes via a paracellular shunt pathway. Acidification is mediate...
متن کاملInfluence of peritubular protein on solute absorption in the rabbit proximal tubule. A specific effect on NaCl transport.
The effect of removal of peritubular protein on the reabsorption of various solutes and water was examined in isolated rabbit proximal convoluted tubules (PCT) perfused in vitro. In 22 PCT perfused with ultrafiltrate (UF) and bathed in serum, volume absorption (Jv) was 1.44 nl/mm per min and potential difference (PD) was -3.6 mV. When these same PCT were bathed in a protein-free UF, Jv was redu...
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ژورنال
عنوان ژورنال: Kidney International
سال: 1990
ISSN: 0085-2538
DOI: 10.1038/ki.1990.249