Effect of vitamin E supplementation on hypoxia-induced oxidative damage in male albino rats.
BACKGROUND
There is growing evidence that free radicals mediated oxidative injury due to inadequate oxygen availability is an important factor in various pathologies at high altitude. Since vitamin E is known to protect the cells from oxidative damage due to its potent antioxidant properties, the present study was carried out to explore the effect of vitamin E supplementation on various hematological and biochemical parameters in hypoxia-induced oxidative stress in albino rats.


METHODS
The experiments were conducted on male albino rats by intermittently exposing them to a simulated altitude of 7,576 m (25,000 ft), daily for 6 h for 15 d at 32 +/- 2 degrees C. The control group was fed vehicle only (1% Tween 80) and the experimental group was given vitamin E (40 mg per rat x d(-1)) orally, 5 d prior to and during the period of hypoxic exposure. The variables studied include: hemoglobin, hematocrit, RBC deformability index, alpha-tocopherol level, malondialdehyde (MDA), reduced glutathione (GSH), oxidized glutathione (GSSG), lactate dehydrogenase (LDH) and protein level in blood/plasma and various tissues.


RESULTS
Significant increase in hematocrit and hemoglobin and decrease in RBC deformability index was observed on exposure to hypoxia while vitamin E supplementation maintained them at the normal level. Hypoxia led to the decrease in plasma vitamin E and blood glutathione (GSH) level and two-fold increase in the plasma malondialdehyde (MDA) level. Vitamin E supplementation, on the other hand, resulted in less of an increase in MDA and increased the GSH concentration significantly. LDH activity, which was elevated on exposure to hypoxia, was arrested on vitamin E supplementation.


CONCLUSIONS
The results indicate that vitamin E supplementation results in preventing oxidative damage due to high altitude stress.
Ilavazhagan
G
G
Defence Institute of Physiology and Allied Sciences, Timarpur, Ministry of Defence, Delhi, India. defphysiol@satyam.net.in
Bansal
A
A
Prasad
D
D
Thomas
P
P
Sharma
S K
SK
Kain
A K
AK
Kumar
D
D
Selvamurthy
W
W
D000531:Altitude; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D019587:Dietary Supplements; D005978:Glutathione / Q000097:blood; D000860:Hypoxia / Q000503:physiopathology*; D007770:L-Lactate Dehydrogenase / Q000097:blood; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D018384:Oxidative Stress / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014810:Vitamin E / Q000494:pharmacology*
D000975:Antioxidants; D014810:Vitamin E; D008315:Malondialdehyde; D007770:L-Lactate Dehydrogenase; D005978:Glutathione