Send to

Choose Destination
See comment in PubMed Commons below
J Appl Physiol (1985). 2001 Sep;91(3):1193-8.

Downregulation of nitric oxide in the brain of mice during their hypoxic preconditioning.

Author information

Department of Neurobiology, Capital University of Medical Sciences, Beijing 100054, China.


An animal model of hypoxic preconditioning was produced in mice by repeated exposure to autohypoxic condition. The animals' tolerance times to hypoxia were 1.7, 1.8, 2.1, and 2.3 times longer in runs 2, 3, 4, and 5, respectively, than that in run 1, and their oxygen consumption and heart and respiration rates were progressively and significantly slowed down during the repetitive exposure to hypoxia. L-Arginine concentration, nitric oxide (NO) synthase-positive cells, NO synthase activity, and NO content in the whole brain and the subregions telencephalon, diencephalon, and brain stem were significantly increased during the first exposure and were, instead of continuing to increase, significantly decreased in run 4 after the second and third exposure. Tolerance times under the hypoxic condition were significantly shortened and prolonged when preadministration of L-arginine and its analog, respectively, was made. These results indicate that NO in the brain is downregulated under condition of hypoxic preconditioning and negatively involved in increased tolerance to hypoxia.

[Indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire
    Loading ...
    Support Center