title: GABA concentrations in the striatum following repetitive cerebral ischemia.
abstract: GABAergic neurons in the striatum are very sensitive to the effects of ischemia. The progressive decline in striatal GABA following transient forebrain ischemia in gerbils may be secondary to either a decreased production or an increase in reuptake mechanisms or both. The current experiment was designed to evaluate release of GABA by stimulation with K+ or inhibition of its uptake with nipecotic acid or their combination (K+ nipecotic) after repetitive forebrain ischemia in gerbils by in-vivo microdialysis on Days 1, 3, 5, and 14 following the insult. Infusion of nipecotic acid or potassium chloride, resulted in a significant increase in extracellular GABA. This response was significantly decreased in the post-ischemic animals. The synergistic effect of increased GABA concentrations by the infusion of nipecotic acid + potassium chloride seem in the controls was not evident in the post-ischemic animals. In conclusion, though there is a reduction in the extracellular GABA concentrations in the first week following an ischemic insult, restorative mechanisms are operative in the second week as seen by the increasing GABA concentrations.
authors.affiliation: Royal University Hospital, Saskatoon, SK, Canada.
authors.forename: T
authors.initials: T
authors.lastname: Mainprize
authors.forename: A
authors.initials: A
authors.lastname: Shuaib
authors.forename: S
authors.initials: S
authors.lastname: Ijaz
authors.forename: R
authors.initials: R
authors.lastname: Kanthan
authors.forename: H
authors.initials: H
authors.lastname: Miyashita
authors.forename: J
authors.initials: J
authors.lastname: Kalra
mesh_terms: D000818:Animals; D003342:Corpus Striatum / Q000098:blood supply / Q000378:metabolism*; D004357:Drug Synergism; D005849:Gerbillinae; D002546:Ischemic Attack, Transient / Q000378:metabolism*; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D017551:Microdialysis; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D014179:Neurotransmitter Uptake Inhibitors / Q000494:pharmacology*; D009557:Nipecotic Acids / Q000494:pharmacology*; D011189:Potassium Chloride / Q000494:pharmacology*; D011392:Proline / Q000031:analogs & derivatives*; D012008:Recurrence; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
chemical_list: D014179:Neurotransmitter Uptake Inhibitors; D009557:Nipecotic Acids; C030278:nipecotic acid; D005680:gamma-Aminobutyric Acid; D011189:Potassium Chloride; D011392:Proline; C010983:homoproline