Authors: Wolfgang Krick Natascha A Wolff Gerhard Burckhardt
Publish Date: 2000/08/05
Volume: 441, Issue: 1, Pages: 125-132
Abstract
pAminohippurate PAH and urate are secreted into the proximal tubule lumen across the brushborder membrane Here we used brushborder membrane vesicles from pig kidney to study PAH and urate transport Efflux and influx of 3HPAH were influenced by K+diffusion potentials indicating electrogenic PAH transport An outsideinside PAH concentration difference accelerated voltagesensitive Na+coupled dglucose uptake as efficiently as did an outsideinside Cl– concentration difference suggesting comparable conductances for PAH and Cl– in brushborder membrane vesicles Up to 1 mM of the uricosurics indacrinone tienilic acid losartan and probenecid as well as of the stilbenes DIDS and SITS and of the loop diuretics furosemide and bumetanide inhibited voltagedriven PAH uptake but not or only slightly voltagedriven Cl– uptake Voltagedriven 14Curate uptake however was inhibited by 01 mM DIDS 02 mM losartan and 05 mM probenecid to a similar extent as 3HPAH uptake One millimolar pyrazinoic acid oxonate xanthine and adenosine inhibited neither 3HPAH nor 14Curate uptake These results suggest that PAH and urate share an anion conductance which is distinct from the Cl– conductance and is probably not the same as a recently identified urate channel LealPinto E et al J Biol Chem 272617–625 1997
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