-transparent.png){kind=logo}
The effect of luminal bicarbonate concentration on proximal tubular acidification was studied. Rat proximal convoluted tubules were perfused in vivo with solutions of varying bicarbonate concentration, and bicarbonate absorption was measured using microcalorimetry. Bicarbonate absorption was found to increase linearly with mean luminal bicarbonate concentrations up to 45 mM, but above this level it showed evidence of partial saturation. Bicarbonate permeability was measured and found to be 2.6 +/- 0.3 x 10(-7) cm2/s. Using this permeability, net bicarbonate absorption could be divided into two parallel components, both sensitive to luminal bicarbonate concentration: 1) proton secretion and 2) a passive bicarbonate leak. Proton secretion, when examined as a function of luminal bicarbonate concentration, exhibited saturation kinetics with an apparent Km of 16 mM and a Vmax of 200 pmol . mm-1 . min-1.
R J Alpern, and
M G Cogan, and
F C Rector
January 1995,
Renal physiology and biochemistry,
R J Alpern, and
M G Cogan, and
F C Rector
July 1969,
The American journal of physiology,
R J Alpern, and
M G Cogan, and
F C Rector
December 1973,
The Journal of clinical investigation,
R J Alpern, and
M G Cogan, and
F C Rector
July 1984,
The Journal of physiology,
R J Alpern, and
M G Cogan, and
F C Rector
November 1985,
The Journal of physiology,
R J Alpern, and
M G Cogan, and
F C Rector
October 1997,
The American journal of physiology,
R J Alpern, and
M G Cogan, and
F C Rector
September 1983,
Pflugers Archiv : European journal of physiology,
R J Alpern, and
M G Cogan, and
F C Rector
January 1987,
Mineral and electrolyte metabolism,
R J Alpern, and
M G Cogan, and
F C Rector
July 1993,
Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas,
R J Alpern, and
M G Cogan, and
F C Rector
February 1983,
The American journal of physiology,
