Lidocaine protects hippocampal neurons against ischemic damage by preventing increase of extracellular excitatory amino acids: a microdialysis study in Mongolian gerbils.
Extracellular levels of amino acids in the hippocampal CA1 region of the gerbil were analyzed by a microdialysis-HPLC procedure. Transient forebrain ischemia produced significant increase in aspartate, glutamate, glycine and taurine (760%, 1070%, 190% and 1210%, respectively), and neuronal blockade by perfusion with a lidocaine (4 mM)-containing medium resulted in 67%, 79%, 58% and 59% reduction in the peak values of each amino acid, respectively. On the other hand, an intracerebroventricular administration of lidocaine, 0.8 mumol or more, produced a protective effect against delayed damage of hippocampal CA1 pyramidal cells, which was caused by bilateral carotid artery occlusion for 4 min. The results suggest that lidocaine may protect neurons against ischemic damage, by preventing the ischemia-induced rise of extracellular concentration of excitatory amino acid.
Department of Anesthesiology and Resuscitology, Ehime University School of Medicine, Japan.
T
T
Fujitani
N
N
Adachi
H
H
Miyazaki
K
K
Liu
Y
Y
Nakamura
K
K
Kataoka
T
T
Arai
D000818:Animals; D002545:Brain Ischemia / Q000473:pathology* / Q000517:prevention & control*; D018846:Excitatory Amino Acids / Q000378:metabolism*; D005849:Gerbillinae; D006624:Hippocampus / Q000473:pathology*; D008012:Lidocaine / Q000627:therapeutic use*; D008297:Male; D017551:Microdialysis; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D017966:Pyramidal Cells / Q000187:drug effects / Q000378:metabolism
D018846:Excitatory Amino Acids; D008012:Lidocaine