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Home / Equine Research Bank / Biochem J / Characterization of a novel Na+-independent amino acid trans...
The Biochemical journal1985; 227(1); 13-20; doi: 10.1042/bj2270013

Characterization of a novel Na+-independent amino acid transporter in horse erythrocytes.

Abstract: Horse erythrocytes are polymorphic with respect to L-alanine permeability. The present investigation compared the specificity, kinetics and cation-dependence of erythrocyte amino acid transport in two groups of thoroughbred horses, those with erythrocyte L-alanine permeabilities in the range 5-15 mumol/h per litre of cells (0.2 mM extracellular L-alanine, 37 degrees C) (transport-negative type) and those with L-alanine permeabilities in the range 450-700 mumol/h per litre of cells (transport-positive type). Transport-positive cells are shown to possess a novel high-affinity, stereospecific, Na+-independent transporter selective for neutral amino acids of intermediate size. This carrier system (provisional designation asc) operates preferentially in an exchange mode and is functionally absent from erythrocytes of transport-negative-type horses.
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Publication Date: 1985-04-01 PubMed ID: 3994678PubMed Central: PMC1144803DOI: 10.1042/bj2270013Google Scholar: Lookup
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Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

This study explores a new type of amino acid transporter found in horse red blood cells, which operates independently of sodium and is particularly active in horses presenting high permeability for L-alanine.

Objective of the Study

  • The focus of the research was to investigate the variation in amino acid transport, specifically L-alanine, in the red blood cells of thoroughbred horses. The researchers divided the horses into two groups based on their erythrocyte (red blood cell) L-alanine permeabilities.

Types of Horses in the Study

  • The first group had L-alanine permeabilities ranging from 5-15 micromoles per hour per litre of cells, labeled as the “transport-negative type”.
  • The second group had L-alanine permeabilities ranging 450-700 micromoles per hour per litre of cells, described as the “transport-positive type”.

Discovery of the Novel Transporter

  • The study discovered a previously unidentified high-affinity amino acid transporter in the erythrocytes of the transport-positive type horses.
  • This transporter, labeled as the asc system, is selective for neutral amino acids of intermediate size.
  • The transporter operates in an exchange mode, meaning it carries one substance into the cell as it transports another substance out.
  • Importantly, this transporter operates independently of sodium. This aspect contrasts with many other types of cellular transporters, which require the presence of ions like sodium to function.
  • The asc system was found to be absent from the red blood cells of the transport-negative type horses.

Implications of Study

  • Understanding these differences in amino acid transporters could have significant implications for equine health and disease management. For instance, if this transporter’s activity is linked to certain diseases, identifying its presence could help diagnose or manage these conditions.
  • The study’s findings also provide further context about biological variations in not just horses, but potentially other species as well. The discovery of the asc system brings new insights regarding the diversity of cellular transportation mechanisms.

Cite This Article

APA
Fincham DA, Mason DK, Young JD. (1985). Characterization of a novel Na+-independent amino acid transporter in horse erythrocytes. Biochem J, 227(1), 13-20. https://doi.org/10.1042/bj2270013

Publication

The Biochemical journal
ISSN: 0264-6021
NlmUniqueID: 2984726R
Country: England
Language: English
Volume: 227
Issue: 1
Pages: 13-20

Researcher Affiliations

Fincham, D A
    Mason, D K
      Young, J D

        MeSH Terms

        • Alanine / metabolism
        • Amino Acids / blood
        • Animals
        • Biological Transport / drug effects
        • Cations, Monovalent / pharmacology
        • Cysteine / pharmacology
        • Erythrocytes / drug effects
        • Erythrocytes / metabolism
        • Horses
        • Sodium / pharmacology
        • Substrate Specificity

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