Adenosine by activating A1 receptors prevents GABAA-mediated actions during hypoxia in the rat hippocampus.
The relative contribution of adenosine and gamma-aminobutyric acid (GABA) for the hypoxia-induced depression of field excitatory postsynaptic potentials in the CA1 area of rat hippocampal slices, was investigated. It is concluded that both adenosine and GABA, by activating A1 and GABAA receptors, could be responsible for the inhibition of synaptic transmission during hypoxia, but the action of endogenous GABA becomes evident only when the adenosine A1 receptor action is precluded.
Laboratory of Pharmacology, Gulbenkian Institute of Science, Oeiras, Portugal.
R
R
Lucchi
S
S
Latini
A
A
de Mendonça
A M
AM
Sebastião
J A
JA
Ribeiro
D000241:Adenosine / Q000494:pharmacology*; D000818:Animals; D015687:Cell Hypoxia; D005071:Evoked Potentials / Q000187:drug effects; D018756:GABA Antagonists / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology*; D002534:Hypoxia, Brain; D066298:In Vitro Techniques; D009118:Muscimol / Q000494:pharmacology; D010721:Phosphinic Acids / Q000494:pharmacology; D011412:Propanolamines / Q000494:pharmacology; D017966:Pyramidal Cells / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D011963:Receptors, GABA-A / Q000502:physiology*; D018047:Receptors, Purinergic P1 / Q000502:physiology*; D009435:Synaptic Transmission / Q000187:drug effects; D014970:Xanthines / Q000494:pharmacology; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
D018756:GABA Antagonists; D010721:Phosphinic Acids; D011412:Propanolamines; D011963:Receptors, GABA-A; D018047:Receptors, Purinergic P1; D014970:Xanthines; C085075:CGP 55845A; D009118:Muscimol; D005680:gamma-Aminobutyric Acid; C051360:1,3-dipropyl-8-cyclopentylxanthine; D000241:Adenosine