Fluorescence probe measurement of the pH of the transferrin microenvironment during iron uptake by rat bone marrow erythroid cells.
Fluorescence probe measurements of the transferrin micro-environment during iron uptake by rat erythroid cells revealed that part of the transferrin is taken up in an acidic environment. The pH of this intracellular transferrin environment is 5.7. When rat erythroid cell precursors are incubated with diferric transferrin then in the incubation medium monoferric transferrins TfNFe and TfFeC appear. In view of the known instability of TfNFe at acidic pH, TfNFe cannot arise after endocytosis of Tf2Fe in acid vesicles at pH below 6.0. The results support the existence of a mechanism other than endocytosis in the iron uptake process in rat erythroid cells.
D000818:Animals; D001854:Bone Marrow Cells; D004912:Erythrocytes / Q000378:metabolism*; D005456:Fluorescent Dyes; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007501:Iron / Q000378:metabolism*; D007525:Isoelectric Focusing; D008297:Male; D008985:Monensin / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D014168:Transferrin / Q000378:metabolism*
D005456:Fluorescent Dyes; D014168:Transferrin; C028283:diferric transferrin; D008985:Monensin; D007501:Iron