Contribution of metabotropic glutamate receptors to the depression of excitatory postsynaptic potentials during hypoxia.
We tested the hypothesis that activation of metabotropic glutamate receptors (mGluR) might contribute to the depression of excitatory postsynaptic potentials during hypoxia. The experiments were performed on hippocampal slices taken from young (12-14 days old) Wistar rats. The depression induced by hypoxia (14 min) was not modified in the presence of either the non-selective mGluR antagonist (which blocks mainly group I and II mGluR), MCPG (500 microM) or the selective group III mGluR antagonist, MPPG (500 microM). However, in experiments performed in the presence of the selective adenosine A1 receptor antagonist, DPCPX (50 nM), part of the hypoxia-induced depression could be prevented by MPPG (500 microM). Activation of group III mGluR may contribute to the hypoxia-induced depression, but this contribution is only revealed when adenosine A1 receptors are blocked.
de Mendonça
A
A
Laboratory of Neurosciences, Faculty of Medicine, Lisbon, Portugal.
Ribeiro
J A
JA
D000409:Alanine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D001565:Benzoates / Q000494:pharmacology*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology*; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology*; D005998:Glycine / Q000031:analogs & derivatives* / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology*; D000860:Hypoxia; D066298:In Vitro Techniques; D058915:Purinergic P1 Receptor Antagonists; D051381:Rats; D017208:Rats, Wistar; D018094:Receptors, Metabotropic Glutamate / Q000037:antagonists & inhibitors / Q000502:physiology*; D013569:Synapses / Q000187:drug effects / Q000502:physiology; D013997:Time Factors; D014970:Xanthines / Q000494:pharmacology
D001565:Benzoates; D018691:Excitatory Amino Acid Antagonists; D058915:Purinergic P1 Receptor Antagonists; D018094:Receptors, Metabotropic Glutamate; D014970:Xanthines; C101185:alpha-methyl-4-phosphonophenylglycine; C079694:alpha-methyl-4-carboxyphenylglycine; C051360:1,3-dipropyl-8-cyclopentylxanthine; D000409:Alanine; D005998:Glycine