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Modulation of the NMDA receptor by polyamines
K Williams1, C Romano, M A Dichter
1Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia 19104-6084.
Life Sciences
|January 1, 1991
Summary
Researchers discovered a distinct polyamine recognition site on the NMDA receptor. This site, modulated by polyamines like spermine and spermidine, offers potential therapeutic targets for neurological disorders.
Area of Science:
- Neuroscience
- Biochemistry
- Pharmacology
Background:
- Biochemical and electrophysiological studies suggest a polyamine recognition site on the NMDA receptor complex.
- This site is distinct from known binding sites for glutamate, glycine, Mg++, Zn++, and open-channel blockers.
Purpose of the Study:
- To investigate the role and characteristics of the polyamine recognition site on the NMDA receptor.
- To identify compounds acting as agonists, antagonists, or inverse agonists at this site.
- To explore the therapeutic potential of modulating this site.
Main Methods:
- Biochemical binding assays using [3H]MK-801.
- Electrophysiological recordings of NMDA-elicited currents in cultured neurons.
- Testing natural and synthetic polyamines for their effects on ligand binding and receptor activity.
Main Results:
- Endogenous polyamines (spermine, spermidine) act as agonists, increasing open-channel blocker binding and NMDA currents.
- Various natural and synthetic polyamines were classified as partial agonists, antagonists, and inverse agonists.
- Polyamines also influence glutamate and glycine binding, potentially via a separate site.
Conclusions:
- A distinct polyamine recognition site on the NMDA receptor modulates receptor function.
- This site represents a novel therapeutic target for conditions such as neurotoxicity, epilepsy, and neurodegenerative diseases.