Abstract |
Considering that adenosine decreases glutamate release from brain slices by stimulating presynaptic A1 receptors, we have attempted to modulate glutamate release in vivo during global ischemia with an agonist (R- phenylisopropyladenosine, R-PIA) of A1 receptors. Extracellular hippocampal glutamate was sampled by microdialysis and measured by HPLC. Conscious rats were submitted to transient global ischemia for 20 min. Ischemia induced a significant increase (10 fold) in extracellular glutamate. R-PIA (20 micrograms/kg) administered i.p. 30 min before ischemia significantly reduced (-64%) glutamate release. Conversely, R-PIA (100 microM) continuously infused through the hippocampal dialysis probe did not significantly modify glutamate efflux. The efficiency of infused R-PIA was evidenced by the decrease (-47%) of glutamate release induced by veratridine depolarization. These results indicate that the depressive action of R-PIA during ischemia results from various effects which are not restricted to a local action on the hippocampus.
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Authors | A Héron, F Lasbennes, J Seylaz |
Journal | Neuroscience letters
(Neurosci Lett)
Vol. 147
Issue 2
Pg. 205-8
(Dec 07 1992)
ISSN: 0304-3940 [Print] Ireland |
PMID | 1491809
(Publication Type: Journal Article)
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Chemical References |
- Diazonium Compounds
- Glutamates
- Sulfanilic Acids
- Phenylisopropyladenosine
- Veratridine
- diazobenzenesulfonic acid
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Topics |
- Animals
- Blood Pressure
(drug effects)
- Brain Ischemia
(metabolism)
- Chromatography, High Pressure Liquid
- Diazonium Compounds
(metabolism)
- Electroencephalography
- Glutamates
(metabolism)
- Injections, Intraperitoneal
- Male
- Phenylisopropyladenosine
(pharmacology)
- Rats
- Rats, Wistar
- Sulfanilic Acids
(metabolism)
- Veratridine
(pharmacology)
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