1 research outputs found
Regional differences in antioxidative response of rat brain after cranial irradiation
In order to examine
if differences
in activity and inducibility of
antioxidative enzymes in rat cerebral cortex and hippocampus are underlying
their different sensitivity to radiation, we exposed four-day-old female
Wistar rats to cranial radiation of 3 Gy of γ-rays. After isolation
of hippocampus and cortex 1 h or 24 h following exposure, activities of
copper-zinc superoxide dismutase (CuZnSOD), manganese superoxide dismutase
(MnSOD) and catalase (CAT) were measured and
compared to unirradiated controls. MnSOD protein levels were determined by SDS-PAGE
electrophoresis and Western blot analysis. Our results showed that CuZnSOD activity in hippocampus and cortex
was significantly decreased 1 h and 24 h after irradiation with 3 Gy of γ-rays. MnSOD activity in both brain regions was also
decreased 1 h after irradiation. 24 h following exposure, manganese SOD
activity in hippocampus almost achieved control values, while in cortex it
significantly exceeded the activity of the relevant controls. CAT activity in
hippocampus and cortex remained stable 1 h, as well as 24 h after irradiation
with 3 Gy of γ-rays.
MnSOD protein level in hippocampus and cortex decreased 1 h after irradiation
with 3 Gy of γ-rays. 24 h after exposure, MnSOD protein level in cortex
was similar to control values, while in hippocampus it was still
significantly decreased. We have
concluded that regional differences in MnSOD radioinducibility are regulated
at the level of protein synthesis, and that they represent one of the main
reasons for region-specific radiosensitivity of the brain