NH4+ transport pathways in cells of medullary thick ascending limb of rat kidney. NH4+ conductance and K+/NH4+(H+) antiport.
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چکیده
منابع مشابه
Effects of ammonium on intracellular pH in rat medullary thick ascending limb: mechanisms of apical membrane NH4+ transport
UNLABELLED The renal medullary thick ascending limb (MTAL) actively reabsorbs ammonium ions. To examine the effects of NH4+ transport on intracellular pH (pHi) and the mechanisms of apical membrane NH4+ transport, MTALs from rats were isolated and perfused in vitro with 25 mM HCO3(-)-buffered solutions (pH 7.4). pHi was monitored using the fluorescent dye BCECF. In the absence of NH4+, the mean...
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Fluorescence and electrophysiological methods were used to determine the effects of intracellular pH (pHi) on cellular NH4+/K+ transport pathways in the renal medullary thick ascending limb of Henle (MTAL) from CD1 mice. Studies were performed in suspensions of MTAL tubules (S-MTAL) and in isolated, perfused MTAL segments (IP-MTAL). Steady-state pHi measured using 2,7-biscarboxyethyl-5(6)-carbo...
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Net Clabsorption in the mouse medullary thick ascending limb of Henle (mTALH) involves a furosemide-sensitive Na+:K+:2 Clapical membrane symport mechanism for salt entry into cells, which occurs in parallel with a Ba'-sensitive apical K+ conductance. The present studies, using the in vitro microperfused mouse mTALH, assessed the concentration dependence of blockade of this apical membrane K+-co...
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ACTIVE REABSORPTION of Na across the thick ascending limb of Henle (TALH) plays an essential role in the urine concentrating mechanism, as it generates and maintains the axial osmolality gradient in the outer medulla. Na enters the TALH cell mostly through apical Na -K -2Cl (NKCC2) cotransporters, to a lesser extent through Na /H (NHE3) exchangers, and it is extruded at the basolateral membrane...
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To assess whether metabolic acidosis per se regulates rBSC-1, the rat medullary thick ascending limb (MTAL) apical Na+-K+(NH4+)-2Cl- cotransporter, rat MTALs were incubated for 16 h in an acid 1:1 mixture of Ham's nutrient mixture F-12 and Dulbecco's modified Eagle's medium. Cotransport activity was estimated in intact cells and membrane vesicles by intracellular pH and 22Na+ uptake measurement...
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ژورنال
عنوان ژورنال: Journal of Biological Chemistry
سال: 1994
ISSN: 0021-9258
DOI: 10.1016/s0021-9258(17)31742-8