title: Zinc deficiency exacerbates loss in blood-brain barrier integrity induced by hyperoxia measured by dynamic MRI.
abstract: Using dynamic Magnetic Resonance Imaging (dMRI), blood-brain barrier (BBB) permeability (k(PSrho)) and tissue interstitial leakage space (v(e)) were evaluated in zinc-deficient (ZnDF) male weanling Wistar rats following 3 days exposure to hyperoxia (85% O2). Temporal monitoring of T1-weighted MR image changes, following a bolus intravenous injection of gadolinium-DTPA, allowed estimation of BBB integrity. Three-day exposure of hyperoxia caused a marginal loss of BBB integrity, reflected in a slight increase in kPSrho and v(e), observed in both the animals fed adequate zinc (ZnAL) and pair-fed controls (ZnPF). However, zinc deficiency resulted in a significant increase in both kPSrho and v(e), indicating a severely disturbed BBB. In addition MR-visible free water was elevated in ZnDF brains following hyperoxia treatment indicating that a loss of BBB integrity may be associated with neuronal edema. The diminished BBB integrity may be free-radical mediated as the ratio of oxidized to reduced glutathione (GSSG:GSH) was significantly elevated.
authors.affiliation: Department of Human Biology and Nutritional Sciences, University of Guelph, Ontario, Canada. mikenose@sten.sunnybrook.utoronto.ca
authors.forename: M D
authors.initials: MD
authors.lastname: Noseworthy
authors.forename: T M
authors.initials: TM
authors.lastname: Bray
mesh_terms: D000818:Animals; D001812:Blood-Brain Barrier / Q000502:physiology*; D001834:Body Water / Q000378:metabolism; D001921:Brain / Q000473:pathology; D018496:Hyperoxia / Q000473:pathology / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D015032:Zinc / Q000172:deficiency* / Q000378:metabolism / Q000502:physiology
chemical_list: D015032:Zinc