Neurochemical Research

, Volume 18, Issue 6, pp 647–654 | Cite as

Uptake and metabolism of glutamate and aspartate by astroglial and neuronal preparations of rat cerebellum

  • V. L. Raghavendra Rao
  • Ch. R. K. Murthy
Original Articles


Astrocytes, neuronal perikarya and synaptosomes were prepared from rat cerebellum. Kinetics of high and low affinity uptake systems of glutamate and aspartate, nominal rates of14CO2 production from [U−14C]glutamate, [U−14C]aspartate and [1−14C]glutamate and activities of enzymes of glutamate metabolism were studied in these preparations. The rate of uptake and the nomial rate of production of14CO2 from these amino acids was higher in the astroglia than neuronal perikarya and synaptosomes. Activities of glutamine synthetase and glutamate dehydrogenase were higher in astrocytes than in neuronal perikarya and synaptosomes. Activities of glutaminase and glutamic acid decarboxylase were observed to be highest in neuronal perikarya and synaptosomes respectively. These results are in agreement with the postulates of theory of metabolic compartmentation of glutamate while others (presence of glutaminase in astrocytes and glutamine synthetase in synaptosomes) are not. Results of this study also indicated that (i) at high extracellular concentrations, glutamate/aspartate uptake may be predominantly into astrocytes while at low extracellular concentrations, it would be into neurons (ii) production of α-ketoglutarate from glutamate is chiefly by way of transamination but not by oxidative deamination in these three preparations and (iii) there are topographical differences glutamate metabolism within the neurons.

Key Words

Glutamate aspartate astrocytes neurons synaptosomes uptake CO2 production 


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Copyright information

© Plenum Publishing Corporation 1993

Authors and Affiliations

  • V. L. Raghavendra Rao
    • 1
    • 2
  • Ch. R. K. Murthy
    • 1
  1. 1.School of Life SciencesUniversity of HyderabadHyderabadIndia
  2. 2.Neuroscience Research Unit, André-Viallet Clinical Research Center, Hôpital Saint-LucUniversity of MontrealMontrealCanada

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