Hypoxia/hypoglycemia-induced amino acid release is decreased in vitro by preconditioning.
The aim of this study was to investigate the effects of preconditioning on amino acid neurotransmitter release, induced by hypoxia/hypoglycaemia, from rat brain cortical slices. Tissue, perfused with artificial cerebrospinal fluid (aCSF) at 37 degrees C with zero glucose and gassed with 95% nitrogen and 5% carbon dioxide, showed a fivefold increase in glutamate release with little effect on gamma-aminobutyric acid (GABA) release. Preconditioning, with three 5-min periods of hypoxia/hypoglycaemia preceding continuous hypoxia/hypoglycaemia, significantly decreased glutamate release whilst significantly elevating GABA release. These results suggest that GABA may reduce the release of glutamate and consequently decrease the neurotoxic effects of glutamate.
Johns
L
L
Department of Pharmacology, Therapeutics and Toxicology, University of Wales College of Medicine, Heath Park, Cardiff, CF14 4XN, United Kingdom.
Sinclair
A J
AJ
Davies
J A
JA
D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000098:blood supply*; D007003:Hypoglycemia / Q000378:metabolism* / Q000503:physiopathology; D002534:Hypoxia, Brain / Q000378:metabolism* / Q000503:physiopathology; D019194:Ischemic Preconditioning; D008297:Male; D051381:Rats; D017208:Rats, Wistar
D000596:Amino Acids