Comparison of the properties of gamma-aminobutyric acid and L-glutamate uptake into synaptic vesicles isolated from rat brain

J Neurochem. 1989 Mar;52(3):946-51. doi: 10.1111/j.1471-4159.1989.tb02546.x.


Rat brain synaptic vesicles exhibit ATP-dependent uptake of gamma-[3H]amino-n-butyric acid ([3H]GABA) and L-[3H]glutamate. After hypotonic shock, the highest specific activities of uptake of both L-glutamate and GABA were recovered in the 0.4 M fraction of a sucrose gradient. The uptakes of L-glutamate and GABA were inhibited by similar, but not identical, concentrations of the mitochondrial uncoupler carbonyl cyanide m-chlorophenylhydrazone and the ionophores nigericin and gramicidin, but they were not inhibited by the K+ carrier valinomycin. N,N'-Dicyclohexyl-carbodiimide and N-ethylmaleimide, Mg2+-ATPase inhibitors, inhibited the GABA and L-glutamate uptakes similarly. Low concentrations of Cl- stimulated the vesicular uptake of L-glutamate but not that of GABA. The uptakes of both L-glutamate and GABA were inhibited by high concentrations of Cl-. These results indicate that the vesicular GABA and L-glutamate uptakes are driven by an electrochemical proton gradient generated by a similar Mg2+-ATPase. The vesicular uptake mechanisms are discussed in relation to other vesicle uptake systems.

Publication types

  • Comparative Study

MeSH terms

  • Adenosine Triphosphate / pharmacology
  • Animals
  • Biological Transport, Active / drug effects
  • Brain / ultrastructure*
  • Ca(2+) Mg(2+)-ATPase / antagonists & inhibitors
  • Carbonyl Cyanide m-Chlorophenyl Hydrazone / pharmacology
  • Cell Fractionation
  • Centrifugation, Density Gradient
  • Chlorides / pharmacology
  • Electrochemistry
  • Glutamates / metabolism*
  • Glutamic Acid
  • Gramicidin / pharmacology
  • Male
  • Nigericin / pharmacology
  • Protons
  • Rats
  • Rats, Inbred Strains
  • Synaptic Vesicles / metabolism*
  • gamma-Aminobutyric Acid / metabolism*


  • Chlorides
  • Glutamates
  • Protons
  • Gramicidin
  • Glutamic Acid
  • Carbonyl Cyanide m-Chlorophenyl Hydrazone
  • gamma-Aminobutyric Acid
  • Adenosine Triphosphate
  • Ca(2+) Mg(2+)-ATPase
  • Nigericin