ABSTRACT
The effect of dietary zinc deficiency on the enzymatic components of free radical defense system was observed in the skin of rats. We measured the concentration of serum zinc and the enzymatic activities of CuZn superoxide dismutase(CuZn SOD), glucose-6-phosphate dehydrogenase(GGPDH) and glutathione reductase (GSH-RD). The serum zinc level was sig nificantly lower in the zinc-deficient group compared to the zinc-supplemented group after 8 weeks of consuming the diet(P<0.01). CuZn SOD activity was not different between the two groups after 4 weeks. The Zn deficient group showed the significantly decreased activity of G6PDH after 4 and 8 weeks of consuming the diet(P<0.01). The activity of GSH-RD was increased in the zinc-deficient group compared to the supplemented group after 4 weeks of consuming the diet(P<0.01), but after 8 weeks the activity was not different between the two groups. From the results obtained, it could be concluded that GSH-RD may contribute to the oxygen free radical defense system in zinc deficiency in the earlier weeks of consum ing the zinc-deficient diet.
Subject(s)
Animals , Rats , Diet , Glucose-6-Phosphate , Glucosephosphate Dehydrogenase , Glutathione Reductase , Oxygen , Skin , Superoxides , ZincABSTRACT
Weanling Wistar rats were fed a modified AIN-76 diet ad libitum for 25 to 57 days, either copper-deficient (0.49mg/kg; CuD) or copper-adequate (6.44mg/kg;CuA). The effects of dietary copper deficiency on the enzymatic components of the primary free radical defense system-super-oxide dismutase (SOD), catalasc (CAT) and glutathione peroxidase (GSH-Px), lipoperoxides (LPO) and serum hemolysin were examined. The amount of LPO exhibited no significant change even though SOD activity decreased significantly in the tissues of CuD rats, which indicated that Cu-ZnSOD activity responded directly to copper status of the body but the compromises in the overall protection against free radicals were not evident. The profound reduction in scrum hemolysin in CuD rats suggests that humoral immune function is copper dependent. The results also suggest that as an index of evaluating copper nutriture CuZnSOD is more sensitive than hemoglobin to copper deficiency.