title: Direct experimental occlusion of the distal middle cerebral artery induces high reproducibility of brain ischemia in mice.
abstract: Several investigators have used murine models to investigate the pathophysiology of brain ischemia. The focal ischemic model is a closer approximation to human stroke which includes a necrotic core, penumbra, and undamaged tissue. Occlusion of a unilateral artery, especially the middle cerebral artery (MCA), is performed in this model, but collateral circulation often induces variation of ischemic lesions both qualitatively and quantitatively. It is likely that the more proximal the artery which is unilaterally occluded is, the more inconsistent the outcomes. The present study was designed to examine the reproducibility of infarct lesion by distal or proximal artery occlusion. Direct occlusion of the distal MCA was performed and compared with unilateral common carotid artery occlusion (CCAO) in C57BL/6 mice. Direct MCA occlusion (MCAO) consistently induced ischemic lesions in cortical areas. All model animals (n=14) survived 24 h after occlusion, and exhibited a maximum infarct volume (20.0 +/- 5.0%). In contrast, permanent and transient unilateral CCAO models had mortality rates of 62.5 and 25.0%, and showed severe to absent lesions with the infarct volumes of 29.0 +/- 20.8 and 33.2 +/- 24.2%, respectively. In conclusion, distal MCAO produces high reproducibility of ischemic insults and survivability compared to unilateral CCAO. Thus, distal MCAO is a useful method for the focal ischemic model.
authors.affiliation: Department of Biomedical Science, Graduate School of Agricultural and Life Sciences, University of Tokyo, Japan.
authors.forename: Mutsuki
authors.initials: M
authors.lastname: Kuraoka
authors.forename: Takahisa
authors.initials: T
authors.lastname: Furuta
authors.forename: Takashi
authors.initials: T
authors.lastname: Matsuwaki
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Omatsu
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Ishii
authors.forename: Shigeru
authors.initials: S
authors.lastname: Kyuwa
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Yoshikawa
mesh_terms: D000818:Animals; D020520:Brain Infarction / Q000209:etiology / Q000473:pathology; D002545:Brain Ischemia / Q000209:etiology / Q000401:mortality / Q000473:pathology*; D017536:Carotid Artery, Common / Q000601:surgery; D004195:Disease Models, Animal; D020244:Infarction, Middle Cerebral Artery / Q000209:etiology / Q000473:pathology*; D008026:Ligation; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D020768:Middle Cerebral Artery / Q000601:surgery; D015203:Reproducibility of Results; D013047:Specific Pathogen-Free Organisms; D015996:Survival Rate