title: Collateral circulation prevents masticatory muscle impairment in rat middle cerebral artery occlusion model.
abstract: The rat suture middle cerebral artery occlusion (MCAO) is a frequently used animal model for investigating the mechanisms of ischemic brain injury. During suture MCAO, transection of the external carotid artery (ECA) potentially restrains blood flow and impairs masticatory muscle and other ECA-supported territories, consequently influencing post-operation animal survival. This study was aimed at investigating the effect of ECA transection on the hemodynamic alterations using a novel synchrotron radiation (SR) angiography technique and magnetic resonance imaging in live animals. Fifteen male adult Sprague-Dawley rats were used in this study. Animals underwent MCAO, in which the ECA was transected. SR angiography was performed before and after MCAO. Rats then underwent magnetic resonance imaging (MRI) to detect the tissue lesion both intra- and extra-cranially. Animals with SR angiography without other manipulations were used as control. High-resolution cerebrovascular morphology was analyzed using a novel technique of SR angiography. The masticatory muscle lesion was further examined by hematoxylin and eosin staining. MRI and histological results showed that there was no masticatory muscle lesion at 1, 7 and 28 days following MCAO with ECA transection. In normal condition, the ECA and its branch external maxillary artery were clearly detected. Following ECA transection, the external maxillary artery was still observed and the blood supply appeared from the anastomotic branch from the pterygopalatine artery. SR angiography further revealed the inter-relationship of hemisphere extra- and intra-cranial vasculature in the rat following MCAO. Transection of the ECA did not impair masticatory muscles in rat suture MCAO. Interrupted blood flow could be compensated by the collateral circulation from the pterygopalatine artery.
authors.affiliation: Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, People's Republic of China.
authors.forename: Falei
authors.initials: F
authors.lastname: Yuan
authors.affiliation: Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, People's Republic of China.
authors.forename: Xiaojie
authors.initials: X
authors.lastname: Lin
authors.affiliation: Department of Radiology, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025, People's Republic of China.
authors.forename: Yongjing
authors.initials: Y
authors.lastname: Guan
authors.affiliation: Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, People's Republic of China.
authors.forename: Zhihao
authors.initials: Z
authors.lastname: Mu
authors.affiliation: Department of Radiology, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025, People's Republic of China.
authors.forename: Kemin
authors.initials: K
authors.lastname: Chen
authors.affiliation: Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, People's Republic of China.
authors.forename: Yongting
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, People's Republic of China.
authors.forename: Guo-Yuan
authors.initials: GY
authors.lastname: Yang
mesh_terms: D000818:Animals; D003097:Collateral Circulation / Q000502:physiology; D004195:Disease Models, Animal; D007091:Image Processing, Computer-Assisted; D020244:Infarction, Middle Cerebral Artery / Q000000981:diagnostic imaging*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008410:Masticatory Muscles / Q000098:blood supply*; D011859:Radiography; D011897:Random Allocation; D051381:Rats; D012680:Sensitivity and Specificity; D017356:Synchrotrons
keywords: angiography; collateral circulation; masticatory muscle; middle cerebral artery occlusion