We examined whether excess iron supplementation to a low-protein diet (7% casein) caused oxidative damage, and whether an additional treatment of total body irradiation (TBI) enhanced this oxidative damage. A preliminary study showed that more than 1 week of feeding a low protein diet decreased plasma iron, increased liver non-heme iron, and also enhanced TBI-induced chromosomal damage in bone marrow. Based on these findings, mice were fed on the low-protein diet for 1 week and then on the same diet with and without excess iron (2.5% carbonyl iron) for an additional week, before being exposed to TBI (0.5Gy) or not. Iron supplementation significantly increased the non-heme iron and lipid peroxidation in the liver, but did not increase chromosomal damage in the bone marrow. Simultaneous treatment with TBI and iron supplementation did not influence the degree of chromosomal damage or lipid peroxidation due to each treatment. These findings indicate that excess iron supplementation with a low-protein diet did not induce chromosomal damage in the bone marrow, but did induce marked lipid peroxidation in the liver.
