Placental iron transfer regulation in the haemophagous region of the badger placenta: ultrastructural localization of ferritin in trophoblast and endothelial cells.

The haemophagous region of the badger (Meles meles L.) placenta is involved in iron transfer, and maternal erythrocytes are the only source of iron for the fetus. This ultrastructural study provides morphological evidence of placental ferritin iron storage intervening if haem-iron uptake exceeds fetal needs. Such placental ferritin is assumed to play an active role in iron transfer regulation. In this paper we demonstrate that this regulatory process of iron transfer by storage in placental ferritin occurs on at least two levels: the cytotrophoblast and the fetal endothelium. The latter could then act as a final monitor in the transfer of iron into the fetal circulation.