Neurochemical Research

, Volume 17, Issue 1, pp 107–114 | Cite as

Isolation and characterization of endogenous modulators for GABA system

  • M. Yarom
  • J. Bao
  • X. -W. Tang
  • E. Wu
  • Y. H. Lee
  • W. H. Tsai
  • J. -Y. Wu
Original Articles


Pig brain extracts from both soluble and membrane fractions were found to contain potent inhibitors for GABA synthesizing enzyme, GAD, referred to as endogenous GAD inhibitors (EGIs) and for the binding of GABA agonist, muscimol, referred to as muscimol binding inhibitors (MBIs). EGIs and MBIs were first purified through gel-filtration Bio-Gel P-2 columns, in which multiple activity peaks were observed. One of them appears to be co-eluted with eitherl-glutamate or GABA. However, others are clearly separated froml-glutamate or GABA. EGIs were found to be low MW (<1,800 dalton), heat and acid-base stable, negatively charged, non hydrophobic substances. MBIs were found to be low MW (<1,800 dalton) neutral or positively charged substances. MBIs had no effect on [3H]flunitrazepam (FNZP) binding, indicating that they are not endogenous benzodiazepine receptor ligands and they may act specifically on GABA binding site.

Key Words

Endogenous inhibitors glutamate decarboxylase GABAA receptor GABA 


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Copyright information

© Plenum Publishing Corporation 1992

Authors and Affiliations

  • M. Yarom
    • 1
  • J. Bao
    • 1
  • X. -W. Tang
    • 1
  • E. Wu
    • 1
  • Y. H. Lee
    • 1
  • W. H. Tsai
    • 2
  • J. -Y. Wu
    • 1
  1. 1.Department of Physiology and Cell Biology, Division of Biological SciencesUniversity of KansasLawrence
  2. 2.Institute of Biomedical SciencesAcademia SinicaTaipeiTaiwan ROC

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