The role of oligodendrocyte-derived transferrin in the transport and regional accumulation of iron has been studied in myelin-deficient (md) rats, which lack functional oligodendrocytes and have an almost complete depletion of transferrin in the brain, although they have normal peripheral levels of transferrin. The regional uptake of 59Fe into the brain has been studied autoradiographically in md and littermate control rats. Differences in uptake were found in only three of the 28 regions studied. These results suggest that the uptake and distribution of iron is not impaired in the md rat despite a markedly reduced level of brain transferrin. The choroid plexus contains high levels of transferrin mRNA and it is therefore likely that transferrin synthesized by choroid plexus epithelial cells can mediate the transport of iron within the brain.
