Fig. 5.
Vitamin C and ANF decrease E2-induced changes in antioxidant enzyme activities. Female ACI rats were treated with cholesterol, E2, cholesterol + vitamin C, E2 + vitamin C, ANF or E2 + ANF as described in the Materials and Methods section. The activity levels of SOD and GPx were measured in mammary tissue and mammary tumor tissue from animals in each of the treatment groups. Fold changes in enzyme activity were calculated for animals in the E2, E2 + vitamin C and E2 + ANF groups relative to enzyme activity levels in age-matched control animals. Fold change data for tumor tissue were determined by comparing enzyme activity levels in tumor tissue to levels observed in non-tumor mammary tissue from age-matched controls. These data are reported as an average of values obtained for at least seven different animals ± standard error. (A) Fold changes in GPx activity in mammary tissue from rats treated with E2, E2 + vitamin C and E2 + ANF. (B) Fold changes in SOD activity in mammary tissue from rats treated with E2, E2 + vitamin C and E2 + ANF. The symbol ‘*’ indicates a P value <0.05 relative to each group's respective controls. The symbol ‘‡’ indicates a P value <0.05 comparing the E2 + vitamin C and E2 + ANF groups to the E2 group.