The subcellular distribution of transferrin in rat choroid plexus studied with immunogold labelling of ultracryosections.
Choroid plexus epithelium from third ventricle choroid plexus of 2-3-week-old rats was examined for transferrin-like immunoreactivity. In 5 microns paraffin sections most epithelial cells exhibited a pronounced immunoperoxidase staining for transferrin. The ultrastructure of the epithelium in question was examined by conventional electron microscopy. Immunolabelling of ultracryosections with IgG-gold, protein-A gold or protein-A gold-antiprotein-A protein-A gold showed an intense labelling of the basal extracellular space. The lateral intercellular space and the luminal surface showed a more variable labelling; no labelling of the tight junction zone was seen. Intracellularly a distinct labelling of the 'uptake and disposal pathway' (the endosomal-lysosomal system) was observed, but also the synthetic machinery (rough endoplasmic reticulum, stacked Golgi membranes) showed a characteristic labelling. Thus it seems likely that both uptake and synthesis of transferrin occur in choroid plexus epithelial cells.
Møllgård
K
K
Department A, Panum Institute, University of Copenhagen, Denmark.
Balslev
Y
Y
D000818:Animals; D002831:Choroid Plexus / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D005629:Frozen Sections; D007150:Immunohistochemistry; D008297:Male; D008854:Microscopy, Electron / Q000379:methods; D051381:Rats; D014168:Transferrin / Q000378:metabolism*
D014168:Transferrin