Cationic and anionic amino acid transport studies in rat red blood cells.
The transport of L-proline, L-lysine and L-glutamate in rat red blood cells has been studied. L-proline and L-lysine uptake were Na(+)-independent. When the concentration dependence was studied both showed a non-saturable uptake assimilable to a difussion-like process, with high Kd values (0.718 and 0.191 min-1 for L-proline and L-lysine respectively). Rat red blood cells showed high impermeability to L-glutamate. No sodium dependence was observed and the Kd value was low (0.067 min-1). Our results show firstly, that rat red blood cells do not have amino acid transport systems for anionic and cationic amino acids and secondly that erythrocytes show no sodium-dependent L-proline transport, and that these cells are very permeable to this amino acid.
Felipe
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A
Departament de Bioquímica i Fisiologia, Universitat de Barcelona, Spain.
Viñas
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O
Remesar
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X
D000409:Alanine / Q000378:metabolism*; D000818:Animals; D001692:Biological Transport / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D004912:Erythrocytes / Q000378:metabolism*; D005260:Female; D005971:Glutamates / Q000378:metabolism*; D018698:Glutamic Acid; D008239:Lysine / Q000378:metabolism; D011392:Proline / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors
D005971:Glutamates; D018698:Glutamic Acid; D011392:Proline; D008239:Lysine; D000409:Alanine