In vivo EPR estimation of bilateral hippocampal antioxidant ability of rats with epileptogenesis induced by amygdalar FeCl3 microinjection.
OBJECTIVE
To measure the neural antioxidant function in the hippocampus of rats with epileptogenesis induced by microinjection of FeCl3 into the amygdala using the decay rate of the nitroxide radical as estimated by L-band electron paramagnetic resonance (EPR) spectroscopy.


METHODS
Region-selected intensity determination (RSID) was used for the estimation of the nitroxide decay ratio. It is possible to estimate the in vivo hippocampal antioxidant ability using the half-life of the EPR signal of the blood-brain barrier-permeable nitroxide radical. Rats were microinjected with aqueous FeCl3 into the right amygdaloid body. Recording from chronically implanted depth electrodes showed the development of spike discharges with recurrent seizures arising from amygdalar regions with propagation into both hippocampi. Rats with unilateral aqueous FeCl3 lesions were injected systemically with the nitroxide radical and then had EPR for RSID estimation at 5, 15, and 30 days after the iron salt injection.


RESULTS
The in vivo antioxidant ability of the dorsal hippocampus was significantly decreased bilaterally in animals with FeCl3-induced seizures when compared to the control.


CONCLUSIONS
Neural antioxidant function in the hippocampi of rats with chronic seizures induced by amygdalar FeCl3 was decreased early and both ipsilaterally and bilaterally.
Ueda
Yuto
Y
Section of Psychiatry, Department of Clinical Neuroscience, University of Miyazaki, Miyazaki, Japan. usan@med.miyazaki-u.ac.jp
Yokoyama
Hidekatsu
H
Nakajima
Akira
A
Takaki
Mayuko
M
Nagatomo
Keiko
K
Doi
Taku
T
Willmore
L James
LJ
D000679:Amygdala / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D002712:Chlorides; D002908:Chronic Disease; D004195:Disease Models, Animal; D004567:Electrodes, Implanted; D004578:Electron Spin Resonance Spectroscopy; D004827:Epilepsy / Q000139:chemically induced / Q000378:metabolism; D005290:Ferric Compounds / Q000494:pharmacology*; D005609:Free Radicals / Q000378:metabolism; D007839:Functional Laterality; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D008032:Limbic System / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008845:Microinjections; D009434:Neural Pathways / Q000187:drug effects / Q000378:metabolism; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D009589:Nitrogen Oxides / Q000378:metabolism; D009676:Noxae / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D012640:Seizures / Q000139:chemically induced* / Q000378:metabolism*
D000975:Antioxidants; D002712:Chlorides; D005290:Ferric Compounds; D005609:Free Radicals; D009589:Nitrogen Oxides; D009676:Noxae; C024555:ferric chloride