The fiber diameter was caluculated from the traced outline assuming a circular shape. The diameter of unmyelinated axons were caluculated as described above for the myelinated fibers. The effects of aging and food restriction on the activities and mRNA levels of antioxidant enzymes in rat livers were examined. Until old age, food restriction gave rather decreasing effects on antioxidant enzyme activities. Furthermore, antioxidant enzyme activities and the TBA values of the FR rats were higher at the end of a fasting period than those at the end of a feeding period.
Small bars represent the standard errors of the means.
Each symbol represents a mean value for 5-7 rats with the standard error of the mean. Each column represents a mean value for 5-7 rats with the standard error of the mean. Skin is a tissue exposed most frequently to oxidative stress from the environment in daily life. Age-related changes of oxidative damage and antioxidant enzyme activity in the skin were examined in male Fischer 344 rats aged 6 to 30 months. The contents of phosphatidylcholine hydroperoxide and thiobarbituric acid-reacting substances increased linearly with age.