Influence of Age on Arsenic-Induced Oxidative Stress in Rat

Influence of age on arsenic-induced (0.05, 0.1, and 0.2 lethal dose to 50 % population (LD50) given intraperitoneally) oxidative stress was investigated in young, adult, and old rats at days 7 and 14 post-exposure. A significant dose-dependent effect of arsenic on biochemical variables suggestive of oxidative stress was noted at day 7 following exposure in old rats. The parameters which were significantly altered include an increased reactive oxygen species, thiobarbituric acid reactive substances (TBARS), catalase activity accompanied by a decreased glutathione level. At day 14 following arsenic exposure (0.05 and 0.1 LD50 dose), we observed a significant oxidative injury as evident from significant depletion of superoxide dismutase (SOD) and catalase activities in blood and tissues in addition to more pronounced accumulation of arsenic in blood and tissues. Interestingly, the toxicity was pronounced in young and old rats compared with adult rats. Accumulation of arsenic found to be more prominent in old rats compared with young and adult, which might be due to impaired metabolism with ageing. We conclude that young and old animals are more vulnerable to the arsenic-induced oxidative injury which is comparable with arsenic accumulation in blood and tissues and duration of exposure.