title: Folic acid and its pentaglutamate leak from human erythrocyte ghosts but not from liposomes.
abstract: Liposomes were impermeable to folic acid (PteGlu) and its pentaglutamate (PteGlu5), but both folates leaked from human erythrocyte ghosts at a similar rate. PteGlu5 leaking from ghosts was recovered in suspending medium. This indicates that although neither folate penetrates phospholipid membranes, both can traverse erythrocyte membranes without chemical modification. Reduced monoglutamate folate entered erythrocyte ghosts more slowly than it exited. Leakage of folate in both directions was slower than that of urate which, unlike folate, did not exit faster than it entered human erythrocyte ghosts.
mesh_terms: D001693:Biological Transport, Active; D002463:Cell Membrane Permeability; D004910:Erythrocyte Membrane / Q000378:metabolism*; D004912:Erythrocytes / Q000378:metabolism*; D005492:Folic Acid / Q000031:analogs & derivatives* / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D008081:Liposomes; D011624:Pteroylpolyglutamic Acids / Q000378:metabolism*
chemical_list: D008081:Liposomes; D011624:Pteroylpolyglutamic Acids; C036907:pteroylpentaglutamic acid; D005492:Folic Acid