title: Impact of intracranial blood-flow redistribution on stroke size during ischemia-reperfusion in 7-day-old rats.
abstract: We evaluated color-coded pulsed Doppler ultrasound imaging for the assessment of intracranial blood flow in two models of cerebral ischemia in 7-day-old (P7) rats. Blood-flow velocities (BFVs) were measured in the internal carotid arteries and basilar trunk upstream from the circle of Willis, and in the posterior cerebral arteries downstream (1) before, (2) during left middle cerebral artery electrocoagulation and 50 min-transient either one (I/R-1) or both (I/R-2) common carotid (CCA) arteries occlusion, and (3) after release of CCA(s) occlusion. At 48 h after ischemia 41-48% (I/R-1 model) and 24% (I/R-2 model) of rats did not present a lesion. Those rats displayed increased mean BFV in both right internal carotid artery and basilar trunk in I/R-1 model, and increased mean BFV in the basilar trunk (BT) in I/R-2 model. In contrast, no significant changes in mean BFV were observed in lesioned rats. Furthermore, mean BFV in the BT was inversely correlated to the size of the lesion (r² = 0.75, p<0.0001) in the I/R-2 model. Thus, we demonstrated the protective role of collateral support in P7 rodents. Ultrasound imaging can evidence the establishment or not of the cerebral collateral recruitment, leading to the presence or absence of a lesion. This novel approach should greatly help preclinical studies to reduce animal variability.
authors.affiliation: AP-HP, Hopital Lariboisiere, Physiologie-Explorations Fonctionnelles, Universite-Denis Diderot-Paris7, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Bonnin
authors.forename: Pierre-Louis
authors.initials: PL
authors.lastname: Leger
authors.forename: Nicolas
authors.initials: N
authors.lastname: Deroide
authors.forename: Sébastien
authors.initials: S
authors.lastname: Fau
authors.forename: Olivier
authors.initials: O
authors.lastname: Baud
authors.forename: Marc
authors.initials: M
authors.lastname: Pocard
authors.forename: Christiane
authors.initials: C
authors.lastname: Charriaut-Marlangue
authors.forename: Sylvain
authors.initials: S
authors.lastname: Renolleau
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D001783:Blood Flow Velocity / Q000502:physiology; D020520:Brain Infarction / Q000000981:diagnostic imaging / Q000209:etiology; D002545:Brain Ischemia / Q000150:complications*; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging; D002560:Cerebrovascular Circulation / Q000502:physiology*; D002941:Circle of Willis / Q000000981:diagnostic imaging; D004195:Disease Models, Animal; D008279:Magnetic Resonance Imaging; D051381:Rats; D015424:Reperfusion; D020521:Stroke / Q000209:etiology* / Q000473:pathology*; D017585:Ultrasonography, Doppler, Transcranial