title: Chronic photoperiod disruption does not increase vulnerability to focal cerebral ischemia in young normotensive rats.
abstract: Photoperiod disruption, which occurs during shift work, is associated with changes in metabolism or physiology (e.g. hypertension and hyperglycaemia) that have the potential to adversely affect stroke outcome. We sought to investigate if photoperiod disruption affects vulnerability to stroke by determining the impact of photoperiod disruption on infarct size following permanent middle cerebral artery occlusion. Adult male Wistar rats (210-290 g) were housed singly under two different light/dark cycle conditions ( n = 12 each). Controls were maintained on a standard 12:12 light/dark cycle for nine weeks. For rats exposed to photoperiod disruption, every three days for nine weeks, the lights were switched on 6 h earlier than in the previous photoperiod. T2-weighted magnetic resonance imaging was performed at 48 h after middle cerebral artery occlusion. Disruption of photoperiod in young healthy rats for nine weeks did not alter key physiological variables that can impact on ischaemic damage, e.g. blood pressure and blood glucose immediately prior to middle cerebral artery occlusion. There was no effect of photoperiod disruption on infarct size after middle cerebral artery occlusion. We conclude that any potentially adverse effect of photoperiod disruption on stroke outcome may require additional factors such as high fat/high sugar diet or pre-existing co-morbidities.
authors: 1 Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
authors: Ku Mastura
authors: KM
authors: Ku Mohd Noor
authors: 2 Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK.
authors: Cathy
authors: C
authors: Wyse
authors: 1 Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
authors: Lisa A
authors: LA
authors: Roy
authors: 1 Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
authors: Stephany M
authors: SM
authors: Biello
authors: 1 Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
authors: Christopher
authors: C
authors: McCabe
authors: 1 Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
authors: Deborah
authors: D
authors: Dewar
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure; D001835:Body Weight; D002545:Brain Ischemia / Q000473:pathology*; D021081:Chronobiology Disorders / Q000473:pathology*; D004195:Disease Models, Animal; D004435:Eating; D019270:Fructosamine / Q000097:blood; D020244:Infarction, Middle Cerebral Artery / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D009043:Motor Activity; D017440:Photoperiod; D051381:Rats; D017208:Rats, Wistar; D020521:Stroke / Q000209:etiology / Q000473:pathology
chemical_list: D001786:Blood Glucose; D019270:Fructosamine
keywords: Animal model; circadian rhythm; focal ischemia; hyperglycaemia; photoperiod disruption