1978 Volume 6 Issue 1 Pages 33-38
Thiobarbituric acid reactive substances (TBARS) increased in hepatic microsome fractions from rats aged 3 months as compared with such fractions from 1-month-old rats, though serum TBARS concentration did not differ between both groups. Serum TBARS concentrations became significantly higher in adult rats aged 6-7 and 12-13 months than in those 1 month old. TBARS in microsome fractions increased further by the aging up to 12-13 months and those in mitochondria did not show such clear age-related change, though rats aged 12-13 months had the high TBARS values of mitochondria.
Administration of a diet containing 0.5% α-tocopherol to rats for 1-3 months, lowered the TBARS concentrations in microsomes concomitantly with a decrease of serum TBARS concentration. In these rats, synthetic activities of cholesterol and fatty acid in the hepatic microsomes from acetate or mevalonate were similar in both treated and non-treated control groups. However, the activity was higher in the treated group than in the non-treated control after long-term (up to 6-12 months) feeding of tocopherol. Serum cholesterol, phospholipid and triglyceride concentrations in rats treated with tocopherol for 6-12 months were significantly lower than those in control rats. Hepatic total lipid and triglyceride in rats aged 7-13 months which were higher than those of 1-month-old were tended to decrease by the long-term feeding of tocopherol. By contrast, the hepatic phospholipid content decreased in the non-treated aged rats was less than that in tocopherol treated rats.
After the feeding of a tocopherol deficient diet for 2-16 weeks, TBARS in serum and hepatic subcellular organelles of rats were increased markedly. Although serum lipid concentrations from the rats fed the deficient diet for 2 weeks were significantly higher than those from the controls, there was no significant difference between the two groups after feeding more than 4 weeks. However, a supplement of 2% cholesterol in these diet increased the serum cholesterol and phospholipid concentrations in such tocopherol deficient rats.
Refeeding of a tocopherol-rich diet to the deficient animals reduced the serum lipid concentrations concomitantly with the decrease of TBARS in serum and hepatic subcellular fractions.
The tocopherol deficient animals showed lower synthetic activities of hepatic cholesterol and fatty acid as well as glucose-6-phosphatase in microsomes. These enzyme activities of cholesterol and fatty acid synthesis in the deficient animals tended to be restored by the tocopherol administration.
Nordihydroguaiaretic acid, which was one of the antioxidant drug, did not influence the TBARS in serum and hepatic subcellular organelles, serum lipid concentrations, glucose-6-phosphatase activity and cholesterol and fatty acid synthesis of the microsomes of tocopherol deficient rats.
