Free radical membrane scavengers in myocardium of rats of different age exposed to chronic hypoxia.

Age-dependent changes in myocardial content of vitamin E and total hydrophobic free radical scavengers were estimated in rats of different age. Comparatively high values of vitamin E (0.10-0.12 mg/g fresh tissue) were found in 2-day-old rats. The content of vitamin E was lower in 15- and 60-day-old and 40% higher in 120-day-old rats as compared with new-born animals. Total scavengers were monotonously falling down with age. Vitamin E contribution to total scavengers activity gradually increased in postnatal developmental period of cardiac muscle (from 10% for 2-day-old rats to 50% for 120-day-old rats). Chronic hypoxia (intermittent high altitude hypoxia - 7000 m) had no effect on the levels of cardiac total scavengers and vitamin E when the animals were acclimatized from the 5th postnatal day. Acclimatization of adult animals induced a drop in concentration of vitamin E and did not affect the level of total scavengers.