Bihemispheric ischemic tolerance induced by a unilateral focal cortical lesion.
The purpose of the present study was to determine whether a unilateral photothrombotic brain lesion induces bilateral ischemic tolerance towards a subsequent severe ischemia performed 5 days later. Severe ischemia was induced by transient (1h; t) or permanent (p) occlusion of the middle cerebral artery (MCAO). Rats were sacrificed 24h later. Preconditioning reduced the size of subsequent infarcts in both hemispheres. This effect was most prominent with tMCAO, and ipsilateral preconditioning was more effective than contralateral preconditioning (% of hemispheric volume, mean ± SD: 31.9 ± 3.7 to 19.0 ± 10.3 with ipsilateral tMCAO; 31.9 ± 3.7 to 22.9 ± 4.9 with contralateral tMCAO; 64.7 ± 4.3% to 47.2 ± 12.5% with ipsilateral pMCAO; 64.7 ± 4.3% to 53.1 ± 8.9% with contralateral pMCAO). Ischemic preconditioning was associated with a successive bilateral up-regulation of superoxide dismutases which may be involved in the development of ischemic tolerance. Our data suggest that a focal ischemic brain lesion induces neuroprotective mechanisms in extensive brain areas and thus cause bilateral ischemic tolerance within a certain time window.
Hans Berger Department of Neurology, Jena University Hospital, Friedrich-Schiller-University, Erlanger Allee 101, D-07747 Jena, Germany.
Lena
L
Schumacher
Hans Berger Department of Neurology, Jena University Hospital, Friedrich-Schiller-University, Erlanger Allee 101, D-07747 Jena, Germany. Electronic address: anja.urbach@med.uni-jena.de.
Anja
A
Urbach
Department of Neurology, Heinrich-Heine-University, Moorenstraße 5, D-40225 Düsseldorf, Germany.
Michael
M
Lutzenburg
C. & O. Vogt Institute for Brain Research, University Hospital Düsseldorf, Moorenstrasse 5, D-40225 Düsseldorf, Germany.
Hans-J
HJ
Bidmon
Hans Berger Department of Neurology, Jena University Hospital, Friedrich-Schiller-University, Erlanger Allee 101, D-07747 Jena, Germany; Department of Neurology, Heinrich-Heine-University, Moorenstraße 5, D-40225 Düsseldorf, Germany.
Otto W
OW
Witte
D000818:Animals; D001921:Brain / Q000473:pathology / Q000503:physiopathology*; D002545:Brain Ischemia / Q000473:pathology / Q000503:physiopathology*; D004195:Disease Models, Animal; D007839:Functional Laterality / Q000502:physiology*; D007150:Immunohistochemistry; D020244:Infarction, Middle Cerebral Artery / Q000473:pathology / Q000503:physiopathology*; D019194:Ischemic Preconditioning / Q000379:methods*; D008297:Male; D010775:Photic Stimulation; D011897:Random Allocation; D017208:Rats, Wistar; D012720:Severity of Illness Index; D013482:Superoxide Dismutase / Q000378:metabolism; D013927:Thrombosis; D015854:Up-Regulation / Q000502:physiology; D015431:Weight Loss
D013482:Superoxide Dismutase
Ischemic tolerance; Preconditioning; Rat; Stroke; Superoxide dismutase