Cited by 141Drug Transport and Resistance MechanismsMetabolism and Genetic DisordersPharmacogenetics and Drug Metabolism

Pharmacological and pathophysiological roles of carnitine/organic cation transporters (OCTNs: SLC22A4, SLC22A5 and Slc22a21)

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Tamai, Ikumi·2013·Biopharmaceutics & Drug Disposition

Abstract

The carnitine/organic cation transporter (OCTN) family consists of three transporter isoforms, i.e. OCTN1 (SLC22A4) and OCTN2 (SLC22A5) in humans and animals and Octn3 (Slc22a21) in mice. These transporters are physiologically essential to maintain appropriate systemic and tissue concentrations of carnitine by regulating its membrane transport during intestinal absorption, tissue distribution and renal reabsorption. Among them, OCTN2 is a sodium‐dependent, high‐affinity transporter of carnitine, and a functional defect of OCTN2 due to genetic mutation causes primary systemic carnitine deficiency (SCD). Since carnitine is essential for beta‐oxidation of long‐chain fatty acids to produce ATP, OCTN2 gene mutation causes a range of symptoms, including cardiomyopathy, skeletal muscle weakness, fatty liver and male infertility. These functional consequences of Octn2 gene mutation can be seen clearly in an animal model,jvs mouse, which exhibits the SCD phenotype. In addition, although the mechanism is not clear, single nucleotide polymorphisms of OCTN1 and OCTN2 genes are associated with increased incidences of rheumatoid arthritis, Crohn's disease and asthma. OCTN1 and OCTN2 accept cationic drugs as substrates and contribute to intestinal and pulmonary absorption, tissue distribution (including to tumour cells), and renal excretion of these drugs. Modulation of the transport activity of OCTN2 by externally administered drugs may cause drug‐induced secondary carnitine deficiency. Rodent Octn3 transports carnitine specifically, particularly in male reproductive tissues. Thus, the OCTNs are physiologically, pathologically and pharmacologically important. Detailed characterization of these transporters will greatly improve our understanding of the pathology associated with common diseases caused by functional deficiency of OCTNs. Copyright © 2012 John Wiley & Sons, Ltd.

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  • SLC22A4 and its homologues have significant specificity for ERG and weak activity for various drugs.

    “Subsequent work(87,169–172) has confirmed and reinforced this view of SLC22A4 and its homologues(173) as having significant specificity for ERG, and weak activity for various drugs(174–177).”

    From The biology of ergothioneine, an antioxidant nutraceutical (2020) · cites this paper as [177]

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Authors
Tamai, I.
Affiliations
Kanazawa University (JP)
Corresponding author
Tamai, Ikumi
Venue
Biopharmaceutics & Drug Disposition
Publisher
Wiley
Published
2012-10-14
Volume
34
Issue
1
Pages
29-44
ISSN
  • 0142-2782 (ISSN-L)
  • 1099-081X
OpenAlex
W2127817159
Cited by
141
References
99
Citations by year
2026: 5 · 2025: 2 · 2024: 12 · 2023: 6 · 2022: 6 · 2021: 11 · 2020: 16 · 2019: 11 · 2018: 12 · 2017: 10 · 2016: 14 · 2015: 8 · 2014: 16 · 2013: 10 · 2012: 1
FWCI
1.16
Type
journal article
Language
en
Locations
  • Biopharmaceutics & Drug Disposition (publishedVersion)
  • PubMed (publishedVersion)
  • Institutional Repositories DataBase (IRDB) (submittedVersion, cc-by-nc-nd)
  • Kanazawa University Repository for Academic Resources (DSpace) (Kanazawa University) (submittedVersion, cc-by-nc-nd)
Topics
  • Health Sciences › Medicine › Oncology › Drug Transport and Resistance Mechanisms
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Clinical Biochemistry › Metabolism and Genetic Disorders
  • Life Sciences › Pharmacology, Toxicology and Pharmaceutics › Pharmacology › Pharmacogenetics and Drug Metabolism
Keywords
OCTN1, OCTN2, SLC22A4, SLC22A5, carnitine transport, fatty acid beta-oxidation, drug transporters, intestinal absorption, renal excretion, single nucleotide polymorphisms, rheumatoid arthritis, Crohn's disease, asthma, male infertility, cardiomyopathy
MeSH terms
Solute Carrier Family 22 Member 5, Animals, Carnitine, Carrier Proteins, Humans, Intestinal Absorption, Male, Membrane Proteins, Muscular Diseases, Mutation, Cardiomyopathies, Hyperammonemia, Organic Cation Transport Proteins, Symporters, Mice

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