Increased Na/H antiport activity and abundance in uremic red blood cells.
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| Abstract |
Alterations in red blood cell sodium (Na) transport have been described in chronic renal failure. This study examines the possible impact of uremia on two ouabain-insensitive pathways, the Na/H antiporter and the Cl-/NaCO3- anion exchanger. The Vmax of Na/H antiporter measured as Na influx driven by outward H gradient in acid loaded red blood cells was significantly higher in uremic red blood cells versus controls (60.5 +/- 16.5 vs. 24.5 +/- 5.4 mmol/liter cells/hr, P < 0.025). This increase in activity was associated with an increased abundance of the Na/H antiporter as determined by immunologic analysis using an affinity purified polyclonal antibody to the human NHE-1 isoform of the antiporter. By contrast, the activity of the anion exchanger measured as the DIDS-sensitive lithium (Li) influx was similar in uremic versus control red blood cells (2.10 +/- 0.18 vs. 2.14 +/- 0.20 mmol/liter cells/hr). These experiments, when considered in conjunction with prior studies showing normal Na/Li countertransport in uremia indicate that there is a selective increase in the number of functional Na/H antiporters in uremic red blood cells and that Na/Li countertransport measurements may not be a valid marker for Na/H antiporter activity in red blood cells in patients requiring dialysis for end-stage renal failure.
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| Authors | D B Corry, M L Tuck, S Nicholas, E J Weinman |
| Journal | Kidney international (Kidney Int) Vol. 44 Issue 3 Pg. 574-8 (Sep 1993) ISSN: 0085-2538 [Print] United States |
| PMID | 8231030 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.) |
| Chemical References |
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