Alterations in Protective Enzymes Against Peroxidation in the Central and Peripheral Nervous System of Control and Dysmyelinating Mutant Mice

Abstract

The activities of peroxide-detoxifying enzymes such as superoxide dismutase (SOD), glutathione peroxidase, glutathione reductase, and catalase were measured in the nervous system of neurological dysmyelinating mutants: quaking (Qk), shiverer (Shi), and trembler (Tr) mice. Cu/Zn-SOD activity was higher in the cerebellum of Qk and Shi mice (by 53% and 106%, respectively) in comparison with controls, but it was the same in the cerebellum of Tr mice and their corresponding controls. In contrast, there was no difference in the level of Cu/Zn-SOD activity in the cerebrum of Qk, Shi, and Tr mice and their respective controls. Mn-SOD activity was the same among all the mutants compared to control animals in both cerebrum and cerebellum. In Shi cerebellum, glutathione peroxidase and glutathione reductase activities were slightly decreased (a 21.6% and a 13.2% diminution, respectively), whereas catalase activity in cerebrum and cerebellum was the same among mutants and control mice. In the sciatic nerve from Tr mice, all the enzymatic activities were enhanced: sixfold increase for total SOD, and 2.4-fold, 3.5-fold, and 1.8-fold increase for glutathione peroxidase, glutathione reductase, and catalase, respectively.

Antioxidant Enzymes and Related Trace Elements in Aging Brain Capillaries and Choroid Plexus

“…Copper concentration and SOD activity followed exactly the same pattern in brain capillaries, cerebrum, and cerebellum. A positive correlation between SOD activity and copper content has been reported previously by us and by other investigators (Bohnenkamp and Weser, 1977;Bettger et al, 1978;Paynter et al, 1979;Cloez et al, 1989), and in vivo studies have shown that a decrease in copper concentration is closely associated with decreased SOD activity (Mylroie et al, 1986). The activity of protective enzymes, therefore, may be limited by the availability of essential trace elements.…”

Alteration of α‐Tocopherol Content in the Developing and Aging Peripheral Nervous System: Persistence of High Correlations with Total and Specific (n‐6) Polyunsaturated Fatty Acids

“…In contrast to brain, the PNS has rarely been examined for protection against peroxidation. It has been shown that sciatic nerve exhibits enzymatic defense against peroxidation in dogs (Chvapil et al, 1982) as well as in mice (Cloez et al, 1989) and contains measurable amounts of vitamin E (Vatassery et al, 1986;Gross-Sampson et al, 1988). It is interesting that in a neurological dysmyelinating mutant with an altered PNS, the trembler mouse, we found that enzymatic protection (Cloez et al, 1989) and vitamin E levels (Bourre et al, 1987a) are altered.…”