Luminal acidification in the potassium-replete omcdi: inhibition of
bicarbonate absorption by potassium removal and luminal barium..
Armitage, Frances E., and Charles S. Wingo.
Laboratory of Epithelial Transport, Department of Medicine Division
of Nephrology, Hypertension and Transplantation, University of
Florida and Nephrology Section, Veterans Affairs Medical Center,
Gainesville, FL 32608-1197
APStracts 2:0026F, 1995.
We have previously demonstrated that significant luminal acidification
in the potassium (K)-replete rabbit inner stripe of the outer
medullary collecting duct (OMCDi) occurs via a renal H-K-ATPase
sensitive to several of the gastric H-K-ATPase inhibitors. To
investigate further the mechanism of K-dependent luminal
acidification in K-replete OMCDi, we examined the effects of luminal
K removal, luminal addition of barium (Ba2+) in the presence and
absence of luminal 5.0 nM bafilomycin-A1 (BAF), and basolateral
addition of Ba2+ on net bicarbonate flux (JtCO2, pmol x mm-1 x min-1)
and transepithelial voltage (VT, mV).
Received 4 October 1994; accepted in final form 6 February 1995.
APS Manuscript Number F354-4.
Article publication pending Am. J. Physiol. (Renal Fluid Electrolyte
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 7 March 1995.