title: Differences in intramembrane particle distribution in young and old human erythrocytes.
abstract: The distribution of intramembrane particles in human erythrocytes was studied by freeze-fracture on young and old cells and compared to that obtained after ATP depletion or following addition of a clustering agent. It was shown that intramembrane particles became aggregated and the mean particle density increased as the cells aged. Likewise, both particle aggregation and increased density were found in young cells after moderate ATP depletion. In contrast, mean particle density was markedly reduced in both cell types after exhaustive depletion. Paradoxically, Zn treatment led to decreased particle density in young cells, whilst producing the opposite effect in aged cells. The results suggest that their low ATP content may account for the increased particle density of senescent cells.
authors.affiliation: Laboratory of Membrane Physiology, Institute of Experimental Biology, Faculty of Sciences, Central University of Venezuela, Aptdo. 47114, Caracas 1041-A, Venezuela.
authors.forename: Julio F
authors.initials: JF
authors.lastname: Cordero
authors.forename: Pedro J
authors.initials: PJ
authors.lastname: Rodríguez
authors.forename: Pedro J
authors.initials: PJ
authors.lastname: Romero
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology; D002712:Chlorides / Q000494:pharmacology; D004905:Erythrocyte Aging / Q000187:drug effects / Q000502:physiology*; D004910:Erythrocyte Membrane / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure*; D004912:Erythrocytes / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure*; D005614:Freeze Fracturing; D006801:Humans; D007288:Inosine / Q000494:pharmacology; D007460:Iodoacetamide / Q000494:pharmacology; D013447:Sulfites / Q000494:pharmacology; D017967:Zinc Compounds / Q000494:pharmacology
chemical_list: D002712:Chlorides; D013447:Sulfites; D017967:Zinc Compounds; D007288:Inosine; C016837:zinc chloride; D000255:Adenosine Triphosphate; D007460:Iodoacetamide