Original ArticleCerebrovascular Dysfunction and Blood–Brain Barrier Permeability Induced by Oxidized LDL are Prevented by Apocynin and Magnesium Sulfate in Female RatsSchreurs, Malou P. H. MD*; Cipolla, Marilyn J. PhD*,†,‡Author Information *Departments of Neurological Sciences, †Obstetrics, Gynecology and Reproductive Sciences, and ‡Pharmacology, University of Vermont College of Medicine, Burlington, VT. Reprints: Marilyn J. Cipolla, PhD, Department of Neurological Sciences, University of Vermont, 149 Beaumont Avenue, HSRF 416A, Burlington, VT 05405 (e-mail: [email protected]). Supported by the National Institutes of Health, National Institute of Neurological Disorders and Stroke Grants RO1 NS045940, the National Institute of Neurological Disorders and Stroke Neural Environment Cluster supplement RO1 NS045940-06S1, National Heart Lung and Blood Institute Grant PO1 HL095488 and the Totman Medical Research Trust. The authors report no conflicts of interest. Received June 18, 2013 Accepted September 04, 2013 Journal of Cardiovascular Pharmacology: January 2014 - Volume 63 - Issue 1 - p 33-39 doi: 10.1097/FJC.0000000000000021 Buy Metrics Abstract Oxidized low-density lipoprotein (oxLDL) is elevated during several neurologic conditions that involve cerebral edema formation, including severe preeclampsia and eclampsia; however, our understanding of its effect on the cerebral vasculature is limited. We hypothesized that oxLDL induced blood–brain barrier (BBB) disruption and changes in cerebrovascular reactivity occur through NADPH oxidase–derived superoxide. We also investigated the effect of MgSO4 on oxLDL-induced changes in the cerebral vasculature as this is commonly used in preventing cerebral edema formation. Posterior cerebral arteries from female rats were perfused with 5 µg/mL oxLDL in rat serum with or without 50 µM apocynin or 16 mM MgSO4 and BBB permeability and vascular reactivity were compared. oxLDL increased BBB permeability and decreased myogenic tone that were prevented by apocynin. oxLDL increased constriction to the nitric oxide synthase inhibitor nitro-L-arginine that was unaffected by apocynin. oxLDL enhanced dilation to the NO donor sodium nitroprusside that was prevented by apocynin. MgSO4 prevented oxLDL-induced BBB permeability without affecting oxLDL-induced changes in myogenic tone. Thus, oxLDL seems to cause BBB disruption and vascular tone dysregulation through NADPH oxidase–derived superoxide. These results highlight oxLDL and NADPH oxidase as potentially important therapeutic targets in neurologic conditions that involve elevated oxLDL. © 2014 by Lippincott Williams & Wilkins.