IMMUNOHISTOCHEMICAL LOCALIZATION OF TRANSFERRIN IN THE PRENATAL AND POSTNATAL BOVINE BRAIN

The distribution of transferrin in brains from fetuses (age-range: 1-2 to 8-9 months of gestational age), calves, subadult (between 1 day an d 9 months old) and adult cattle (>12 months old) were examined by imm unohistochemistry. In both pre-and postnatal brains transferrin was pr edominantly found in oligodendrocytes. Furthermore, transferrin immuno staining was present in single to few neurons, within the lumina of ve ssels, in endothelial cells, in epithelial cells of the choroid plexus and in ependymal cells. A caudo-rostral progress in the appearance of transferrin-positive cells was found. In fetuses, transferrin-positiv e mature oligodendrocytes and neurons were not detected before 3-4 mon ths of gestational age. Findings in different brain areas of older fet uses suggest an association between the increase of transferrin-positi ve oligodendrocytes and the process of myelination. In brains from cal ves and subadult cattle a continuous decrease of transferrin-immunorea ctive oligodendrocytes and neurons was noted.