title: Fusion of human erythrocytes induced by uranyl acetate and rare earth metals.
abstract: Incubation of human erythrocytes with either uranyl ions (UO22+) or rare earth metals (La3+, Nd3+, Sm3+, Eu3+, Tb3+, Dy3+ and Yb3+) at 37 degrees C for 30-45 min resulted in the fusion of erythrocytes. Redistribution of membrane-associated particles was observed using colloidal-iron charge labelling and freeze-fracture electron microscopy. The fusion of erythrocytes induced by these agents, unlike Ca2+, did not exhibit the absolute requirement for phosphate. Moreover, agglutination and fusion by these agents was observed in neuraminidase-treated erythrocytes in contrast to Ca2+- and phosphate-induced fusion. Inhibitors of intrinsic transglutaminase activity partially inhibited (35-45%) the fusion induced by UO22+ suggesting that cross-linking of membrane proteins results in protein-free areas of lipid where fusion may be initiated.
mesh_terms: D002118:Calcium / Q000494:pharmacology; D002459:Cell Fusion / Q000187:drug effects; D004912:Erythrocytes / Q000187:drug effects / Q000648:ultrastructure*; D005614:Freeze Fracturing; D006384:Hemagglutination; D006801:Humans; D008674:Metals, Rare Earth / Q000494:pharmacology*; D008854:Microscopy, Electron; D009942:Organometallic Compounds; D014501:Uranium / Q000494:pharmacology*
chemical_list: D008674:Metals, Rare Earth; D009942:Organometallic Compounds; C005460:uranyl acetate; D014501:Uranium; D002118:Calcium