Influence of Different Doses of Irradiation on Oxidant and Antioxidant Systems in the Brain of Guinea Pigs
Meltem Nalca Andrieu
The purpose of this study was to establish the impact of oxidative stress in the damaged brain tissue, irradiated with two different dose levels, a single dose of 8 and 15 Gy. In addition, the histological findings caused by ionizing radiation in the early period was investigated. The levels of MDA, GSH, SOD, CAT, GSH-Px and selenium were estimated in brain tissue. For the histological examination, brain tissues were examined at photo light microscope.
MDA contents of brain after 8 Gy and 15 Gy γ-irradiation were markedly elevated compared with group 1. Brain SOD activity decreased after exposure to 15 Gy γ-irradiation, there was a significant difference compared with group 1 and group 2. Brain GSH-Px activity in group 2 and group 3 was enhanced when compared with group 1. CAT activity of brain after 15 Gy γ-irradiation was markedly decreased compared with group 1 and group 2. GSH levels were significantly lower in group 2 and 3 when compared with group 1. In this study, brain selenium levels were not found to be markedly changed after irradiation. In group 3 basal membrane structure was found to be highly thicker when compared group 1 and group 2.
As a result, in the early period, high doses of ionizing radiation (8 Gy and 15 Gy) influences the oxidant-antioxidant system in guinea-pig brain, after the formation of LPO, antioxidant levels alter and this may play a role in reducing tissue damage caused by RT whereas the histologic changes occur when the dose is increased.