The role of oligodendrocyte-derived transferrin in the transport and r
egional accumulation of iron has been studied in myelin-deficient (md)
rats, which lack functional oligodendrocytes and have an almost compl
ete depletion of transferrin in the brain, although they have normal p
eripheral levels of transferrin. The regional uptake of Fe-59 into the
brain has been studied autoradiographically in md and littermate cont
rol rats. Differences in uptake were found in only three of the 28 reg
ions studied. These results suggest that the uptake and distribution o
f iron is not impaired in the md rat despite a markedly reduced level
of brain transferrin. The choroid plexus contains high levels of trans
ferrin mRNA and it is therefore likely that transferrin synthesized by
choroid plexus epithelial cells can mediate the transport of iron wit
hin the brain.