Abstract

Objectives: We aimed to evaluate the age-related changes of oxidative injury in the brain tissues of rats produced by radiotherapy that is widely used on cancer treatment.

Study Design: Fifty-five male Wistar albino rats [ages of rats were 1, 4, 12 weeks (n=10) and 1 year (n=5)] were divided into four groups. Irradiation were performed on a Cobalt-60 unit using a single fraction of 8 Gy. The brain tissues were homogenized and divided into two portions. One portion was used for the measurement of the malondialdehyde (MDA). The other portion was used for the measurement of the protein concentration, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSHPx) enzyme activities.

Results: The SOD activity decreased significantly in 1-week-old rats (p<0.05). The decreases in GSHPx and CAT activities were more obvious in 1-week and 1-year-old rats than that in others. No significant changes were observed in adolescent and adult rats. The MDA levels of all groups increased. The highest MDA levels were seen in 1-year-old rats (p<0.05).

Conclusion: Ionizing radiation used in radiotherapy affected antioxidant systems and increased MDA levels. These changes were more in the 1-week and 1-year-old rats than in others. This can be due to incomplete development of many systems in newborn rats and the loss of physiological capacities associated with aging in 1-year-old rats.