[Effects of zinc deficiency and supplements on lipid peroxidation and superoxide dismutase in mice]

56 weanling Balb/c mice were assigned to Zn deficiency (ZD, n = 40), pair-fed (PF, n = 8) and fed ad libitum (AL, n = 8) groups according to their sex and weight, ZD mice were fed Zn-deficient (Zn: 1.6 ppm) diet, and PF and AL mice were fed control (Zn: 51.6 ppm) diet. After 6 weeks, 8 mice were taken out from ZD group and killed with all PF and AL mice. Blood and liver were sampled for the assays of Zn, Cu, malondialdehyde (MDA) and superoxide dismutase (SOD). The other 32 ZD mice were divided into four groups and supplemented with 0, 5, 50 and 500 ppm Zn in the Zn-deficient diet respectively. After another 3 weeks they were also killed and used for the measurements of Zn, Cu, MDA and SOD. The results showed that Zn deficiency increased MDA formation and decreased SOD activity in the liver of mice. Supplementation of 5 or 50 ppm Zn for 3 weeks enabled a satisfactory recovery of all the indices in ZD mice. But 500 ppm Zn increased MDA formation and decreased SOD activity further. This could be explained by the secondary Cu deficiency in mice.