title: Brain injury after hypoxia-ischemia in newborn rats: relationship to extracellular levels of excitatory amino acids and cysteine.
abstract: The aim of this study was to follow extracellular concentrations of excitatory amino acids (EAAs) and cysteine during neonatal hypoxia-ischemia (HI) and reflow and to relate these events to the extent of brain damage evaluated 6 h after the insult. Rat pups (PND 7-10) were subjected to unilateral ligation of the common carotid artery and exposed to hypoxia (7.7% O2). Extracellular amino acids were sampled during HI and for 6 h of reperfusion with microdialysis and the levels were correlated with the extent of brain damage at the site of probe placement. The concentrations of glutamate, aspartate and cysteine increased transiently during HI (15 x, 6 x and 3 x, respectively) in the extracellular space and returned to normal or remained slightly elevated during reperfusion. Changes of EAAs and cysteine were similar during HI in the infarcted, undamaged and border-zone regions. During reperfusion the concentrations of glutamate, aspartate and cysteine were higher in infarcted and border-zone areas compared to undamaged tissue. In neonatal rats, the extracellular levels of EAAs during HI do not correspond to the extent of brain injury whereas the EAA concentrations during reflow are related to the extent of infarction.
authors.affiliation: Department of Anatomy and Cell Biology, University of Göteborg, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Puka-Sundvall
authors.forename: M
authors.initials: M
authors.lastname: Sandberg
authors.forename: H
authors.initials: H
authors.lastname: Hagberg
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D001224:Aspartic Acid / Q000378:metabolism; D001921:Brain / Q000378:metabolism*; D001930:Brain Injuries / Q000209:etiology / Q000503:physiopathology*; D017536:Carotid Artery, Common; D003545:Cysteine / Q000378:metabolism*; D018846:Excitatory Amino Acids / Q000378:metabolism*; D005110:Extracellular Space; D005163:Factor Analysis, Statistical; D005260:Female; D018698:Glutamic Acid / Q000378:metabolism; D002534:Hypoxia, Brain / Q000503:physiopathology*; D002546:Ischemic Attack, Transient / Q000503:physiopathology*; D008297:Male; D017551:Microdialysis; D051381:Rats; D017208:Rats, Wistar; D015424:Reperfusion; D018709:Statistics, Nonparametric
chemical_list: D018846:Excitatory Amino Acids; D001224:Aspartic Acid; D018698:Glutamic Acid; D003545:Cysteine