Superoxide Dismutase Activity in Phylogenetically Heterogeneous Regions of the Rat Brain during Repetitive Sessions of Hyperbaric Oxygenation

Resumo

Our study addresses the effect of repetitive sessions of hyperbaric oxygenation (HBO) (2 ATA, 50 minutes, 1 session a day) on superoxide dismutase (SOD) activity as assayed by a chemiluminescent method in the phylogenetically heterogeneous brain structures (brain stem, cerebellum, cerebral hemispheres) of white rats. A study of intact animals (series 1, control) revealed no statistically significant differences in SOD activity between these structures. One HBO session (series 2) stimulated SOD activity in all the brain structures: in the hemispheres, cerebellum and stem by 41, 31 and 66% vs. control, respectively (p < 0.05). After five HBO sessions (series 3), the SOD response intensity in the brain stem exceeded that in the other structures (p < 0.05) and increased by 187% vs. control (p < 0.001). Further continuation of oxygenation up to ten sessions (series 4) was accompanied by a normalization of SOD activity. After eighteen HBO sessions (series 5), the SOD activity level in the cerebellum and cerebral hemispheres somewhat increased compared to the 10th HBO session, although remained closer to the values of the control group than to those of the brain stem. In the brain stem, the SOD activity level exceeded that in intact rats by 46% (p < 0.05).