Middle cerebral artery occlusion in Wistar and Fischer-344 rats: functional and morphological assessment of the model.
Cerebral infarction volume after occlusion of a short proximal segment of the middle cerebral artery (MCA) is reported to be different in Wistar compared to Fischer-344 (F344) rats, in both size and variability. Knowledge about the cause of these differences might enable us to explain and perhaps reduce the variation in infarct volume and create a reproducible model of focal cerebral ischemia in the rat. We investigated in Wistar and F344 rats both the effect of occlusion of a long proximal MCA segment on cerebral infarction volume, visualized by magnetic resonance imaging and histology, and the morphology of the major cerebral arteries. Occlusion of a long proximal MCA segment resulted in a striatal and a small cortical infarction in Wistar and a striatal and sizable cortical infarction in F344 rats (as is the case after occlusion of a short proximal MCA segment). In Wistar rats, however, occlusion of a long proximal MCA segment strongly reduced the variability in infarction volume in comparison to occlusion of a small proximal MCA segment. Analysis of the morphology of the major cerebral arteries showed a significantly higher number of proximal side branches of the long proximal MCA segment in Wistar rates than in F344 rats. We conclude that after short-segment proximal MCA occlusion, extreme variability in cerebral infarction volume in Wistar rats compared to F344 rats may be attributable to a significantly greater number of proximal MCA side branches in Wistar rats than in F344 rats.
Herz
R C
RC
Department of Medical Pharmacology, Rudolf Magnus Institute for Neurosciences, Utrecht University, The Netherlands.
Jonker
M
M
Verheul
H B
HB
Hillen
B
B
Versteeg
D H
DH
de Wildt
D J
DJ
D000818:Animals; D002536:Cerebral Arteries / Q000473:pathology / Q000503:physiopathology; D003250:Constriction; D004195:Disease Models, Animal; D002546:Ischemic Attack, Transient / Q000473:pathology* / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D051381:Rats; D011916:Rats, Inbred F344; D017208:Rats, Wistar; D013045:Species Specificity