To study the effect of oxygen free radicals(OFR) on the occurrence and process of hyperbaric oxygen (HBO) induced convulsions, and the possible mechanism involved.
Methods:105 male SD rats were divided into 10 groups(10~11 in each group): the normal pressure air group, the normoxic hyperbaric nitrogen group, the HBO group, the Vit C-HBO group, the Vit E-HBO group, the SOD-HBO group, the HBO-convulsions group, the Vit C-HBO-convulsions group, the Vit E-HBO-convulsions group and the SOD-HBO convulsions group. The contents of OFR in the brain of rats in each group after respective exposure treatments were measured by means of electron spin resonance (ESR) technique. Pathological changes in the brain of rats and the latent period of oxygen convulsions for all the experimental groups were also observed.
Results:The contents of OFR in the brain of rats in the HBO groups were significantly higher than those in the control group(P﹤0.01). The latent period of oxygen convulsions for the vitamin C-HBO convulsions group and vitamin E-HBO convulsions group were obviously prolonged(P﹤0.01), Electron microscopic examination revealed significant swelling of the nerve fibre and mitochondria with swelling and breaking of nuclear membrane, reduction of ribosome and myelin disorder or severance in the HBO group. But there were no significant differences of the changes between the SOD-HBO and HBO groups(P﹥0.05).
Conclusion:The OFR contents in the brain of rats could be increased by HBO exposure, and OFR was found to be involved in the process of oxygen convulsions. But the elevation of OFR content was not closely correlated with the pressure itself.