title: Prevention of the collapse of pial collaterals by remote ischemic perconditioning during acute ischemic stroke.
abstract: Collateral circulation is a key variable determining prognosis and response to recanalization therapy during acute ischemic stroke. Remote ischemic perconditioning (RIPerC) involves inducing peripheral ischemia (typically in the limbs) during stroke and may reduce perfusion deficits and brain damage due to cerebral ischemia. In this study, we directly investigated pial collateral flow augmentation due to RIPerC during distal middle cerebral artery occlusion (MCAo) in rats. Blood flow through pial collaterals between the anterior cerebral artery (ACA) and the MCA was assessed in male Sprague Dawley rats using in vivo laser speckle contrast imaging (LSCI) and two photon laser scanning microscopy (TPLSM) during distal MCAo. LSCI and TPLSM revealed that RIPerC augmented collateral flow into distal MCA segments. Notably, while control rats exhibited an initial dilation followed by a progressive narrowing of pial arterioles 60 to 150-min post-MCAo (constricting to 80-90% of post-MCAo peak diameter), this constriction was prevented or reversed by RIPerC (such that vessel diameters increased to 105-110% of post-MCAo, pre-RIPerC diameter). RIPerC significantly reduced early ischemic damage measured 6 h after stroke onset. Thus, prevention of collateral collapse via RIPerC is neuroprotective and may facilitate other protective or recanalization therapies by improving blood flow in penumbral tissue.
authors.affiliation: 1 Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada.|2 Neurochemical Research Unit, Department of Psychiatry, University of Alberta, Edmonton, AB, Canada.|3 The First Affiliated Hospital, Shantou University Medical College, Shantou, China.
authors.forename: Junqiang
authors.initials: J
authors.lastname: Ma
authors.affiliation: 2 Neurochemical Research Unit, Department of Psychiatry, University of Alberta, Edmonton, AB, Canada.
authors.forename: Yonglie
authors.initials: Y
authors.lastname: Ma
authors.affiliation: 2 Neurochemical Research Unit, Department of Psychiatry, University of Alberta, Edmonton, AB, Canada.
authors.forename: Bin
authors.initials: B
authors.lastname: Dong
authors.affiliation: 1 Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada.|2 Neurochemical Research Unit, Department of Psychiatry, University of Alberta, Edmonton, AB, Canada.
authors.forename: Mischa V
authors.initials: MV
authors.lastname: Bandet
authors.affiliation: 1 Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada.|4 Department of Medicine, Division of Neurology, University of Alberta, Edmonton, AB, Canada.
authors.forename: Ashfaq
authors.initials: A
authors.lastname: Shuaib
authors.affiliation: 1 Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada.|2 Neurochemical Research Unit, Department of Psychiatry, University of Alberta, Edmonton, AB, Canada.
authors.forename: Ian R
authors.initials: IR
authors.lastname: Winship
mesh_terms: D000818:Animals; D002545:Brain Ischemia / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D002550:Cerebral Veins / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002560:Cerebrovascular Circulation / Q000502:physiology; D003097:Collateral Circulation / Q000502:physiology*; D004195:Disease Models, Animal; D057775:Ischemic Postconditioning / Q000379:methods*; D019194:Ischemic Preconditioning / Q000379:methods*; D008297:Male; D018613:Microscopy, Confocal; D017207:Rats, Sprague-Dawley; D020521:Stroke / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*
keywords: Collateral circulation; ischemia; laser speckle contrast imaging; neuroprotection; two-photon microscopy