Transferrin endocytosis and iron uptake during erythroid cell development.
Electron microscope autoradiography was used to quantitate the uptake of transferrin and transferrin-bound iron by rat erythroid cells at the various stages of development. The capacity of the cells to take up iron closely paralleled their ability to bind transferrin, suggesting that the level of transferrin receptors is the major factor which regulates the rate at which immature erythroid cells can accumulate iron. Maximal transferrin and iron uptake occurred at the basophilic normoblast stage and then decreased progressively during maturation to the reticulocyte. During development, immature rat erythroid cells acquire about twice as much iron from transferrin as is present in the haemoglobin of mature erythrocytes.
D000818:Animals; D001345:Autoradiography; D001491:Basophils / Q000378:metabolism; D001692:Biological Transport; D004705:Endocytosis; D004912:Erythrocytes / Q000378:metabolism*; D007457:Iodine Radioisotopes; D007501:Iron / Q000097:blood* / Q000378:metabolism; D051381:Rats; D012156:Reticulocytes / Q000378:metabolism; D014168:Transferrin / Q000378:metabolism*
D007457:Iodine Radioisotopes; D014168:Transferrin; D007501:Iron