title: Effects of oxygen and glucose deprivation on the expression and distribution of neuronal and inducible nitric oxide synthases and on protein nitration in rat cerebral cortex.
abstract: Changes in the nitric oxide (NO) system of the rat cerebral cortex were investigated by immunohistochemistry, immunoblotting, NO synthase (NOS) activity assay, and magnetic resonance imaging (MRI) in an experimental model of global cerebral ischemia and reperfusion. Brains were perfused transcardially with an oxygenated plasma substitute and subjected to 30 minutes of oxygen and glucose deprivation, followed by reperfusion for up to 12 hours with oxygenated medium containing glucose. A sham group was perfused without oxygen or glucose deprivation, and a further group was treated with the NOS inhibitor N(omega)-nitro-L-arginine methyl ester (L-NAME) before and during perfusion. Global ischemia led to cerebrocortical injury as shown by diffusion MRI. This was accompanied by increasing morphologic changes in the large type I interneurons expressing neuronal NOS (nNOS) and the appearance of nNOS immunoreactivity in small type II neurons. The nNOS-immunoreactive band and calcium-dependent NOS activity showed an initial increase, followed by a fall after 6 hours of reperfusion. Inducible NOS immunoreactivity appeared in neurons, especially pyramidal cells of layers IV-V, after 4 hours of reperfusion, with corresponding changes on immunoblotting and in calcium-independent NOS activity. Immunoreactive protein nitrotyrosine, present in the nuclear area of neurons in nonperfused controls and sham-perfused animals, showed changes in intensity and distribution, appearing in the neuronal processes during the reperfusion period. Prior and concurrent L-NAME administration blocked the changes on diffusion MRI and attenuated the morphologic changes, suggesting that NO and consequent peroxynitrite formation during ischemia-reperfusion contributes to cerebral injury.
authors.affiliation: Department of Neuroanatomy and Cell Biology, Instituto de Neurobiología "Santiago Ramón y Cajal," CSIC, E-28002 Madrid, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Alonso
authors.forename: Julia
authors.initials: J
authors.lastname: Serrano
authors.forename: Ignacio
authors.initials: I
authors.lastname: Rodríguez
authors.forename: Jesús
authors.initials: J
authors.lastname: Ruíz-Cabello
authors.forename: Ana Patricia
authors.initials: AP
authors.lastname: Fernández
authors.forename: Juan Manuel
authors.initials: JM
authors.lastname: Encinas
authors.forename: Susana
authors.initials: S
authors.lastname: Castro-Blanco
authors.forename: María Luisa
authors.initials: ML
authors.lastname: Bentura
authors.forename: María
authors.initials: M
authors.lastname: Santacana
authors.forename: Ana
authors.initials: A
authors.lastname: Richart
authors.forename: Paula
authors.initials: P
authors.lastname: Fernández-Vizarra
authors.forename: Lars Otto
authors.initials: LO
authors.lastname: Uttenthal
authors.forename: José
authors.initials: J
authors.lastname: Rodrigo
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002545:Brain Ischemia / Q000201:enzymology* / Q000473:pathology / Q000503:physiopathology; D002118:Calcium / Q000378:metabolism; D002540:Cerebral Cortex / Q000201:enzymology* / Q000473:pathology / Q000503:physiopathology; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015870:Gene Expression / Q000502:physiology; D005947:Glucose / Q000172:deficiency*; D000860:Hypoxia / Q000201:enzymology* / Q000473:pathology / Q000503:physiopathology; D007150:Immunohistochemistry; D008279:Magnetic Resonance Imaging; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009474:Neurons / Q000201:enzymology* / Q000473:pathology; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D030421:Peroxynitrous Acid / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar / Q000033:anatomy & histology / Q000378:metabolism*; D015427:Reperfusion Injury / Q000201:enzymology / Q000473:pathology / Q000503:physiopathology; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000378:metabolism*
chemical_list: D004791:Enzyme Inhibitors; D030421:Peroxynitrous Acid; D009569:Nitric Oxide; C002744:3-nitrotyrosine; D014443:Tyrosine; D019001:Nitric Oxide Synthase; D005947:Glucose; D002118:Calcium; D019331:NG-Nitroarginine Methyl Ester