Mechanism of methionine-enkephalin modulation of glutamatergic transmission in the rat striatum.
The effect of methionine-enkephalin (Met-Enk) on responses of rat brain neostriatum neurones to microiontophoretic application of glutamate was studied in experiments with extracellular recording of spike activity. Met-Enk administered by microiontophoresis was shown to depress the glutamate-induced responses. In parallel experiments with synaptic membranes isolated from the striatum it was shown that Met-Enk reduces specific binding of glutamate. Analysis of binding curves suggests that the reduced [3H]glutamate binding in the rat striatum membranes was due to decreased binding sites, whereas binding affinity was not changed. The data obtained show that the depressive effect of Met-Enk may be due to the inhibitory influence of the peptide on glutamate binding to its postsynaptic receptors.
Kuznetsov
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Godukhin
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D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects* / Q000502:physiology; D004744:Enkephalin, Methionine / Q000494:pharmacology*; D018691:Excitatory Amino Acid Antagonists; D005971:Glutamates / Q000378:metabolism / Q000502:physiology; D018698:Glutamic Acid; D066298:In Vitro Techniques; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D017470:Receptors, Glutamate; D017981:Receptors, Neurotransmitter / Q000378:metabolism; D009435:Synaptic Transmission
D018691:Excitatory Amino Acid Antagonists; D005971:Glutamates; D017470:Receptors, Glutamate; D017981:Receptors, Neurotransmitter; D018698:Glutamic Acid; D004744:Enkephalin, Methionine