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Uric acid transport in rat renal basolateral membrane vesicles
1Department of Pharmacology, State University of New York, Syracuse, NY 13210.
Biochimica Et Biophysica Acta
|February 23, 1993
Summary
Urate transport in rat kidney cells primarily occurs via a mediated, conductive mechanism. This process is not coupled to chloride, alpha-ketoglutarate, or bicarbonate exchangers.
Area of Science:
- Nephrology
- Renal Physiology
- Molecular Transport
Background:
- Urate transport is crucial for maintaining purine metabolism and preventing conditions like gout.
- Understanding basolateral urate transport in proximal tubules is key to renal urate handling.
Purpose of the Study:
- To investigate the mechanisms of urate transport across the basolateral membrane of rat proximal tubule cells.
- To determine if urate transport involves anion exchange or mediated conductive pathways.
Main Methods:
- Utilized isolated rat renal cortex membrane vesicles.
- Performed tracer flux measurements under various ionic and pH gradient conditions.
- Assessed the role of Na+, Cl-, K+, and pH gradients in urate transport.
Main Results:
- Observed no evidence for alpha-ketoglutarate/urate exchange.
- Found urate uptake was indirectly coupled to Cl- gradients but not directly mediated by Cl-/urate exchange.
- Demonstrated inhibitor-sensitive, concentrative urate accumulation driven by a K+ diffusion potential.
- Ruled out significant involvement of OH-/HCO3- urate exchange.
Conclusions:
- Rat basolateral urate transport is primarily mediated by a conductive mechanism.
- This transport is independent of Cl-, alpha-ketoglutarate, or HCO3- exchange mechanisms.
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