Na+‐dependent high‐affinity uptake of l‐glutamate in cultured fibroblasts

FEBS Letters

Balcar, Vladimir J.¹ 

[1] Department of Anatomy, The University of Sydney, Sydney, NSW 2006, Australia

关键词: Amino acid;    l-Glutamate;    Glutamate analogue;    Agonist and antagonist;    High-affinity uptake;    Fibroblast 3T3;   

DOI  :  10.1016/0014-5793(92)80846-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Uptake of 1 μM[³H]l-glutamate by cultured 3T3 fibroblasts was strongly dependent on extracellular Na⁺; it was reduced by elevated concentrations of K⁺ (60 mM) but it was not influenced by variations in the concentration of Ca²⁺ (0–9.6 mM). d- and l-Asparate, d- and l-threo-3-hydroxyaspartate dl-threo-3-methylaspartate and a few other glutamate derivatives and analogues inhibited the uptake but several close analogues of l-glutamate (including d-glutamate) had no effect, implying that the uptake system is highly structurally selective. The recently identified inhibitor of glutamate uptake in synaptosomal preparations, l-trans-pyrrolidine-2,4-dicarboxylate, was also among the inhibitors. Apparent K _m of the uptake was found to be < 10 μM. The present observations indicate that Na⁺-dependent ‘high-affinity’ uptake of l-glutamate may appear in structures which are apparently unrelated to glutamatergic synaptic transmission in the CNS.

【 授权许可】

Unknown