Nitric oxide synthase and NADPH-diaphorase after acute hypobaric hypoxia in the rat caudate putamen.
Changes in the production system of nitric oxide (NO), a multifunctional biological messenger known to participate in blood-flow regulation, neuromodulation, and neuroprotection or neurotoxicity, were investigated in the caudate putamen of adult rats submitted to hypobaric hypoxia. Employing immunohistochemistry, Western blotting, enzymatic assay, and NADPH-diaphorase staining, we demonstrate that neuronal nitric oxide synthase (nNOS) expression and constitutive nitric oxide synthase (cNOS) activity were transiently activated by 7 h of exposure to a simulated altitude of 8325 m (27,000 ft). In addition, endothelial nitric oxide synthase (eNOS) immunoreactivity and blood vessel NADPH-diaphorase staining peaked immediately after the hypoxic stimulus, whereas inducible nitric oxide synthase (iNOS) expression and activity remained unaltered. Nitrotyrosine formation, a marker of protein nitration, was evaluated by immunohistochemistry and Western blotting, and was found to increase parallel to nitric oxide synthesis. We conclude that the nitric oxide system undergoes significant transient alterations in the caudate putamen of adult rats submitted to acute hypobaric hypoxia.
Departamento de Neuroanatomía y Biología Celular, Instituto de Neurobiología Ramón y Cajal, CSIC, E-28002 Madrid, Spain.
Juan Manuel
JM
Encinas
Ana Patricia
AP
Fernández
Eduardo
E
Salas
Susana
S
Castro-Blanco
Priscila
P
Muñoz
José
J
Rodrigo
Julia
J
Serrano
D000531:Altitude; D000818:Animals; D001808:Blood Vessels / Q000166:cytology / Q000201:enzymology; D015153:Blotting, Western / Q000379:methods; D002452:Cell Count; D004727:Endothelium / Q000166:cytology / Q000201:enzymology; D000860:Hypoxia / Q000201:enzymology*; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D009252:NADPH Dehydrogenase / Q000378:metabolism*; D017072:Neostriatum / Q000166:cytology* / Q000201:enzymology; D009474:Neurons / Q000201:enzymology*; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D052248:Nitric Oxide Synthase Type I; D052247:Nitric Oxide Synthase Type II; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000378:metabolism
C002744:3-nitrotyrosine; D014443:Tyrosine; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; D052247:Nitric Oxide Synthase Type II; C496322:Nos1 protein, rat; C496318:Nos2 protein, rat; D009252:NADPH Dehydrogenase