AJP - Renal Fuel your research with LabChart
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Renal Physiol 267: F695-F701, 1994;
0363-6127/94 $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 Shalmi, M.
Right arrow Articles by Atherton, J. C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Shalmi, M.
Right arrow Articles by Atherton, J. C.

AJP - Renal Physiology, Vol 267, Issue 4 695-F701, Copyright © 1994 by American Physiological Society

ARTICLES

Improved analysis of picomole quantities of lithium, sodium, and potassium in biological fluids

M. Shalmi, J. D. Kibble, J. P. Day, P. Christensen and J. C. Atherton
Department of Pharmacology, University of Copenhagen, Denmark.

The analysis of picomolar lithium, sodium, and potassium by electrothermal atomic absorption spectrophotometry was studied using a Perkin-Elmer Zeeman 3030 spectrophotometer. With ordinary pyrolytically coated graphite tubes, a number of interference effects associated with the sample matrix were observed. In particular, the lithium and potassium absorbance signal was depressed by chloride, an effect shown to be dependent on the preatomization heating. When an in situ tantalum-coated atomization surface was used, matrix interferences observed in lithium and potassium analyses were abolished, and the linear range for the potassium assay was extended. Technical difficulties encountered during sodium analysis at the primary wavelength were effectively circumvented by analysis at a less-sensitive wavelength (303.3 nm), at which tantalum coating also prevented significant chloride interference. The improved microanalyses were employed to reevaluate the handling of lithium, sodium, and potassium along the proximal convoluted tubule (PCT) of the anesthetized rat. The average tubular fluid-to-plasma concentration ratios for lithium [(TF/P)Li] and sodium [(TF/P)Na] were 1.13 +/- 0.08, n = 26, and 0.99 +/- 0.07 (n = 26), respectively. The tubular fluid-to-plasma ultrafiltrate concentration ratio for potassium [(TF/UF)K] was 1.09 +/- 0.05 (n = 13). Ratios did not change significantly with puncture site along the PCT for any of the ions. (TF/P)Li and (TF/UF)K were significantly greater than (TF/P)Na, indicating that lithium and potassium reabsorption do not directly parallel sodium reabsorption in the PCT.


This article has been cited by other articles:


Home page
 Am. J. Physiol. Renal Physiol.Home page
M. Shalmi, T. Jonassen, K. Thomsen, J. D. Kibble, P. Bie, and S. Christensen
Model explaining the relation between distal nephron Li+ reabsorption and urinary Na+ excretion in rats
Am J Physiol Renal Physiol, March 1, 1998; 274(3): F445 - F452.
[Abstract] [Full Text] [PDF]


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