Submitted to: Experimental Biology
Publication Type: Abstract Only
Publication Acceptance Date: 1/12/1999
Publication Date: N/A
Technical Abstract: Aberrant crypt foci (ACF) are preneoplastic lesions for colon cancer. Altered levels of copper-zinc (CuZnSOD) and manganese (MnSOD) superoxide dismutase activities have been implicated in multistage carcinogenesis of both rodents and humans. Dietary factors are potential modulators of both CuZnSOD and MnSOD activity. The purpose of this study was to investigate the interactive effects of dietary copper, manganese and iron on 3,2'- dimethyl-4-aminobiphenyl (DMABP)-induced ACF and superoxide dismutase activities in weanling rats fed two concentrations of copper (0.8 or 5.1 ug Cu/diet), two concentrations of manganese (0.6 or 17 ug Mn/g diet) and two concentrations of iron (37 or 140 ug Fe/g diet). Ingestion of low dietary copper increased the formation of DMABP-induced ACF by 105% (p<0.0001) compared to adequate dietary copper. Ingestion of low dietary manganese caused a 23% increase in the formation of ACF and ingestion of high dietary iron caused an 18% increase in the formation of ACF; however these differences were not statistically significant. Similarly, the highest heart total superoxide dismutase activity was observed in the animals fed adequate dietary copper and manganese and the lowest heart superoxide dismutase activity was observed in the animals fed low dietary copper and manganese. These results suggest that dietary alterations which affect superoxide dismutase activity may affect cancer susceptibility.