Renal nucleoside transporters: physiological and clinical implications
Adam N Elwi1, Vijaya L Damaraju, Stephen A Baldwin
1Department of Oncology and the Membrane Protein Research Group, University of Alberta, Edmonton, Alta., Canada.
Biochemistry and Cell Biology = Biochimie Et Biologie Cellulaire
|January 12, 2007
Summary
The kidney
Area of Science:
- Nephrology and Pharmacology
- Molecular Biology
- Biochemistry
Background:
- Renal handling of nucleosides significantly impacts their systemic availability and potential toxicities.
- Nucleoside transporters (NTs) in renal epithelia mediate selective reabsorption and secretion.
- Human NTs comprise two families: SLC29 (equilibrative, hENTs) and SLC28 (concentrative, hCNTs).
Purpose of the Study:
- To review the renal handling of nucleosides.
- To discuss the physiological and clinical implications of kidney NTs.
- To explore the role of NTs in adenosine signaling and nucleoside drug nephrotoxicity.
Main Methods:
- Review of existing literature on renal nucleoside transport.
- Analysis of the roles of SLC29 and SLC28 transporter families in the kidney.
- Examination of the functional characteristics of specific human NTs (hENTs and hCNTs).
Main Results:
- hCNT1, hCNT2, and hCNT3 are apical Na+-cotransporters; hENT1 and hENT2 are basolateral facilitative transporters, working together for reabsorption.
- hENT3 and hENT4 have less defined roles, with hENT3 being lysosomal and pH-dependent, and hENT4 also transporting monoamines.
- hENT1 may be present at both apical and basolateral membranes, suggesting a role in both secretion and reabsorption.
- Other xenobiotic transporters also contribute to nucleoside and drug metabolite secretion.
Conclusions:
- Kidney NTs are crucial for regulating nucleoside levels and influencing nucleoside drug pharmacokinetics and toxicity.
- Understanding the complex interplay of NTs in renal epithelia is vital for managing nucleoside-based therapies and preventing kidney damage.
- Further research into the specific roles and regulation of all human NTs in the kidney is warranted.
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