AJP - Renal Watch the video to see how APS reaches out to developing nations.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Renal Physiol 245: F584-F592, 1983;
0363-6127/83 $5.00
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Karlmark, B.
Right arrow Articles by Giebisch, G.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Karlmark, B.
Right arrow Articles by Giebisch, G.

AJP - Renal Physiology, Vol 245, Issue 5 584-F592, Copyright © 1983 by American Physiological Society

ARTICLES

Luminal buffer transport in rat cortical tubule: relationship to potassium metabolism

B. Karlmark, P. Jaeger and G. Giebisch

Free-flow micropuncture studies were performed on superficial rat tubules and titratable acid (TA), sodium and potassium concentrations, and tubular pH were measured in control, acutely K-loaded, and chronically K-depleted animals. The proximal tubule is a key site of TA formation. Under control conditions, significant amounts of TA were lost along the loop of Henle. TA delivery (in pmol X min-1) to the late proximal tubule (LP) was 23.66 +/- 2.38 (mean +/- SE), that to the early distal tubule (ED) was 17.24 +/- 1.73, and little further loss occurred along more distally located nephron sites. In acute hyperkalemia, urinary TA excretion (in mumol X min-1) was lower than under control conditions (0.56 +/- 0.04 vs. 1.01 +/- 0.07); TA delivery to the LP (18.50 +/- 1.93) was slightly reduced compared with the controls (a change not reaching statistical significance). TA delivery to the ED was also reduced (11.54 +/- 1.04); significant amounts of TA were lost along the loop of Henle and a significant further loss occurred along the distal tubule since TA delivery to the late distal tubule (LD) was only 7.41 +/- 0.83. As luminal pH along both proximal and distal tubules in K-loaded rats was indistinguishable from that of control rats, a major factor responsible for decreased distal TA formation in K-loaded animals was diminished buffer delivery. In chronic potassium depletion urinary TA excretion was also lowered (0.30 +/- 0.06); only a moderate part of this effect was due to increased pH along the nephron. Increased buffer reabsorption along the proximal tubule (TA delivery to LP was 14.32 +/- 2.01) contributed mainly to the reduced rate of titratable acid excretion.


This article has been cited by other articles:


Home page
 Am. J. Physiol. Renal Physiol.Home page
A. M. Weinstein
A mathematical model of rat distal convoluted tubule. I. Cotransporter function in early DCT
Am J Physiol Renal Physiol, October 1, 2005; 289(4): F699 - F720.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Renal Physiol.Home page
A. M. Weinstein
A mathematical model of rat collecting duct I. Flow effects on transport and urinary acidification
Am J Physiol Renal Physiol, December 1, 2002; 283(6): F1237 - F1251.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Renal Physiol.Home page
A. M. Weinstein
A mathematical model of rat cortical collecting duct: determinants of the transtubular potassium gradient
Am J Physiol Renal Physiol, June 1, 2001; 280(6): F1072 - F1092.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online