Antioxidant enzyme activities in different brain areas of the neurological mutant--pt rabbit.

Cu, Zn-superoxide dismutase (Cu,Zn-SOD), Mn-superoxide dismutase (Mn-SOD), catalase (CAT), peroxidase (POX), glutathione peroxidase(GP) and glutathione reductase (GR) activities were assayed in the brains of genetically selected neurological mutant rabbits pt and their controls. Paralytic tremor (pt) is a spontaneous mutation in rabbit that affects irregular and defective myelination of CNS. Antioxidant enzyme levels were different in three brain regions: brain hemispheres, cerebellum, and brain stem. In brain hemisphere and cerebellum of pt rabbits Mn-SOD and Cu, Zn-SOD activities were elevated. Catalase activity in brain hemispheres and peroxidase activity in the brain stem of pt rabbits were reduced. It was also noticed, that in the pt rabbit the ratio CAT/Cu, Zn-SOD was lower by 20% in the brain hemispheres and by 13% in the cerebellum and the ratio POX/Cu, Zn-SOD was lower by 31.8% in the brain stem. These findings indicated that pt mutations are associated with changes in the antioxidant defense system in the rabbit brain.