Preconditioning enhances the expression of mitochondrial antioxidant thioredoxin-2 in the forebrain of rats exposed to severe hypobaric hypoxia.
The impact of severe hypoxia and preconditioning on the expression of the mitochondrial antioxidant thioredoxin-2 (Trx-2) in rat hippocampus (CA1, CA2, CA3 fields, and dentate gyrus) and neocortex was studied by immunocytochemistry. The preconditioning consisted of three trials of mild hypobaric hypoxia (360 Torr, 2 hr) spaced at 24 hr. The last trial was followed by severe hypobaric hypoxia (180 Torr, 3 hr) 24 hr later. Both in hippocampus and in neocortex, severe hypobaric hypoxia resulted in enhanced Trx-2 expression at 3 hr, followed by a slight decline in Trx-2 levels, which nevertheless remained increased at 24 hr elsewhere except for the CA1 region. The preconditioning considerably augmented severe hypoxia-induced Trx-2 immunoreactivity, affecting both the number of immunoreactive cells and the intensity of immunostaining. The findings suggest a role for Trx-2 in the formation of brain hypoxic/ischemic tolerance accomplished by the preconditioning.
Department of Developmental Biology, Tampere University Medical School, and Department of Pathology, Tampere University Hospital, Tampere, Finland.
Serguei A
SA
Stroev
Tatjana S
TS
Gluschenko
Ekaterina I
EI
Tjulkova
Giannis
G
Spyrou
Elena A
EA
Rybnikova
Michail O
MO
Samoilov
Markku
M
Pelto-Huikko
D000818:Animals; D005786:Gene Expression Regulation / Q000502:physiology; D002534:Hypoxia, Brain / Q000378:metabolism*; D007150:Immunohistochemistry / Q000379:methods; D019194:Ischemic Preconditioning; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism* / Q000627:therapeutic use; D016548:Prosencephalon / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013879:Thioredoxins / Q000378:metabolism* / Q000627:therapeutic use; D013997:Time Factors
D008565:Membrane Proteins; C516113:Txn2 protein, rat; D013879:Thioredoxins