Increase in ferric and ferrous iron in the rat hippocampus with time after kainate-induced excitotoxic injury.
The present study aimed to elucidate the distribution of ferric and ferrous iron in the hippocampus after kainate-induced neuronal injury. A modified Perl's or Turnbull's blue histochemical stain was used to demonstrate Fe3+ and Fe2+ respectively. Very light staining for iron was observed in the hippocampus, in normal or saline-injected rats and 1-day post-kainate-injected rats. At 1 week postinjection, a number of Fe3+-positive, but very few Fe2+-positive, cells were present, in the degenerating CA fields. At 1 month postinjection, large numbers of Fe3+-positive glial cells, and some Fe2+-positive blood vessels, were observed. At 2 months postinjection, large numbers of Fe3+- and Fe2+-positive glial cells were present. The labeled cells had light and electron microscopic features of oligodendrocytes, and were double labeled with CNPase, a marker for oligodendrocytes. The observation of an increasing number of Fe3+- and Fe2+-positive cells in the degenerating hippocampus with time is consistent with the results of a nuclear microscopic study, in which an increasing amount of iron was detected in the degenerating hippocampus after kainate injection. In addition, the present study showed a shift in the oxidation state of the accumulated iron, with more cells becoming Fe2+ at a late stage. A possible consequence of the high amounts of Fe2+ in the hippocampus after kainate injection is that it could promote free radical damage in the lesioned areas.
Wang
X S
XS
Department of Anatomy, National University of Singapore, Singapore 119260.
Ong
W Y
WY
Connor
J R
JR
D000818:Animals; D003287:Contrast Media; D005233:Fatty Alcohols; D005295:Ferrocyanides; D005609:Free Radicals; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D007267:Injections; D007501:Iron / Q000378:metabolism*; D007608:Kainic Acid; D008297:Male; D008854:Microscopy, Electron; D009498:Neurotoxins; D009836:Oligodendroglia / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors
D003287:Contrast Media; D005233:Fatty Alcohols; D005295:Ferrocyanides; D005609:Free Radicals; D009498:Neurotoxins; C029678:Perlan Blue; D007501:Iron; C042827:potassium iron(III) hexacyanoferrate (II); D007608:Kainic Acid