Iron and Transferrin Distribution and Turnover in Iron-Overloaded Rabbits. ∗

Summary

Iron overload was produced in 3 rabbits by intramuscular injection of 1,300 mg iron as iron-dextran, while 3 control rabbits received no treatment. Four years later, plasma iron and transferrin turnover and distribution in the main abdominal organs were studied using plasma-bound radioiron and ¹³¹I-labeled rabbit transferrin. The iron-labeled rabbits when compared with the controls had increased non-heme iron concentrations in liver, spleen, kidney, stomach and intestine; most of the excess iron was in the livers which showed only slight increases of connective tissue around the portal tracts where most of the stainable iron was deposited. Iron-loading was associated with decreased plasma transferrin concentration and total body transferrin and decreased absolute turnover of transferrin. The distribution of transferrin between extravascular and intra-vascular spaces was the same in both groups of rabbits. Hence the decreased plasma transferrin level in the iron-loaded animals was probably due to lowered rates of synthesis.