Kinetics of 2-oxoglutarate uptake by synaptosomes from bovine and rat retina and cerebral cortex and regulation by glutamate and glutamine.
2-Oxoglutarate (2-OG) is a metabolic precursor of glutamate and may be utilized to replenish the neurotransmitter pool. 2-OG is rapidly transported into neurons by a high-affinity carrier that is particularly prevalent in glutamatergic terminals. Here we report the kinetics of [U-14C]2-OG uptake by crude synaptosomal preparations from bovine and rat retina and brain, and the modulatory effects of glutamate and glutamine. In all four tissues, 2-OG uptake was mediated by a high-affinity system (Kt approximately 1 microM) that was subject to negative feedback control by glutamate and biphasic modulation by glutamine (another precursor of neurotransmitter glutamate).
Lehmann
J C
JC
Department of Neurosurgery, Hahnemann University, Philadelphia, PA 19102-1192.
Kapkov
D
D
Shank
R P
RP
D000818:Animals; D002417:Cattle; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism*; D018698:Glutamic Acid / Q000378:metabolism*; D005973:Glutamine / Q000378:metabolism*; D066298:In Vitro Techniques; D007656:Ketoglutaric Acids / Q000493:pharmacokinetics*; D009419:Nerve Tissue Proteins / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D012160:Retina / Q000187:drug effects / Q000378:metabolism*; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism*
D007656:Ketoglutaric Acids; D009419:Nerve Tissue Proteins; D005973:Glutamine; D018698:Glutamic Acid