[Change of NOS activity in hypoxia and cold-induced blood vessels damage and its biological significance].
OBJECTIVE
To explore the therapeutic methods for hypoxia and cold induced blood vessel damage by observing the changes of NO synthase (NOS) activity in hypoxia and development of coldm induced blood vessels damage, and studying the effects of SOD and vitamin C on the changes of NOS activity.


METHODS
The main artery was isolated from Wistar rats and exposed to hypoxia and/or cold environment in vitro. LDH activity was measured using an automatic biochemical analyzer and NOS and SOD activities in blood vessels were analyzed respectively by Griess assay and adrenaline autoxidantion method.


RESULTS
NOS activity in hypoxia, cold and hypoxia-cold damaged vessels decreased by 18.2%, 19.1% and 25.9% respectively after exposure as compared with the control vessels. The changes of NOS activity were time dependent. The NOS activity in damaged vessels was negatively correlated with LDH activity in the culture medium of the respective vessels. The SOD activity in hypoxia and/or cold damaged vessels also decreased significantly. Giving SOD (200 u/ml) or vitamin C (50 mg/ml) immediately after hypoxia and/or cold exposure increased the NOS activity and SOD activity in the damaged vessels significantly, as compared with the non-treatment controls.


CONCLUSIONS
The decrease of NOS activity is closely related to the development of damage induced by hypoxia and/or cold injury. SOD and vitamin C could protect the blood vessels exposed to hypoxia and/or cold from damage, possibly by increasing NOS activity.
Qian
L
L
Institute of Health and Environmental Medicine, Tianjin 300050, China.
Pan
N
N
Gong
J
J
D000818:Animals; D001205:Ascorbic Acid / Q000494:pharmacology; D001808:Blood Vessels / Q000201:enzymology*; D003080:Cold Temperature / Q000009:adverse effects*; D005260:Female; D000860:Hypoxia / Q000097:blood*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008297:Male; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000378:metabolism / Q000494:pharmacology
D007770:L-Lactate Dehydrogenase; D019001:Nitric Oxide Synthase; D013482:Superoxide Dismutase; D001205:Ascorbic Acid