Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10835300 | Nitric Oxide | 2005 | 6 Pages |
Abstract
Nitrate, nitrite, and other nitroso compounds (NOxs) had been proposed as possible nitric oxide (NO) storage molecules. The present work examines, by means of chemiluminescence analysis, changes in NOx serum levels in rats 1Â h before and 24, 48, and 72Â h after exposure to acute hypobaric hypoxia (HH; barometric pressure [PB] 225Â mmHg, oxygen partial pressure [PO2] 48Â mmHg), normobaric hypoxia (NH; PB 716Â mmHg [Jaén city], PO2 48Â mmHg), hypobaric normoxia (HN; PB 225Â mmHg, PO2 150Â mmHg), and normobaric normoxia (NN; PB 716Â mmHg, PO2 150Â mmHg) the latter as a control group. Results show a decrease in NOx levels, which reached significance 24Â h after exposure in HH animals, 4Â h after exposure in the HN and NH groups, and persisted after 48Â h of exposure in the HN group. NOx determinations were also performed in brain (cerebral cortex, hippocampus, decorticated brain [basal ganglia-brainstem] and cerebellum), liver, kidney, lung, and heart homogenates, 72Â h after the experiment, to detect persistent effects when serum NOx levels had returned to basal values. Only in cerebellum (HN group) and hippocampus (HN and NH groups) were NOx levels significantly lower than in controls. We conclude that not only acute hypobaric hypoxia but also either hypobaria or hypoxia alone induce changes in NOx serum levels. Moreover, all three episodes involve a decrease in NOxs, greater and longer-lasting in hypoxia alone than in hypobaria and hypoxia together. The exhaustion of these NO-storage molecules could be critical when, as during a hypoxic episode, the l-arginine/NOS pathway is impaired.
Related Topics
Life Sciences
Biochemistry, Genetics and Molecular Biology
Biochemistry
Authors
J.C. López-Ramos, R. MartÃnez-Romero, F. Molina, A. Cañuelo, E. MartÃnez-Lara, E. Siles, M.A. Peinado,