The Effect of N-Acetylcysteine on Oxidant/Antioxidant Status in Irradiated Rats

N-Acetylcysteine (NAC) is both a strong antioxidant and a glutathione precursor. The effect of NAC on the oxidant/antioxidant status of some tissues of the irradiated rats was investigated. Twenty one rats were assigned to 3 groups; the control group, the irradiation group, for which physiological saline solution was administered as i.p. for three days and then, 9 Gy gamma irradiation was applied, and 3rdirradiation + NAC group for which NAC was adminis-tered as i.p. for three days as 300 mg/kg body weight and then the same dose of irradiation was applied. Upon irradia-tion, the increase determined in malondialdehyde (MDA) was significant in the liver, kidney, and brain tissues of the rats (P˂0.05). While glutathione peroxidase (GSH-Px) activity decreased in all of the tissues and superoxide dismutase (SOD) activity only in the liver (P˂0.01), glutathione (GSH) levels significantly increased in the kidney and ovarium tissues (P˂0.001). While NAC administration returned the increased MDA levels in the kidney and brain as a result of irradiation to normal levels (P˂0.05), it was determined that it did not return the increased MDA levels in the liver tissue to the normal level (P˂0.001). While NAC addition led to a significant increase in GSH levels of the liver, heart, spleen, brain and ovarium tissues compared to both control and irradiation groups, it caused a significant decrease in the kid-ney tissue compared to irradiation group (P˂0.001). As a result of NAC addition, a significant decrease was determined in spleen GSH-Px activity, heart and ovarium SOD activity compared to control and irradiation groups (P˂0.05). It can be asserted that GSH increasing by the addition of NAC is the main antioxidant that has a role in decreasing oxidative stress occurring as a result of irradiation. In the examination of MDA values, it was found that the addition of NAC pro-tected the kidney and brain against the oxidative damage induced by irradiation but NAC addition could remain insuffi-cient for the liver.