title: Effects of aging on antioxidant response and phagocytosis in senescent erythrocytes.
abstract: Red blood cell (RBC) aging is a complex process affected by immunological and biochemical parameters. In this work we studied the antioxidant response in RBC of different ages. We also investigated their interaction with peripheral blood monocytes. Anticoagulated blood samples from 19 O RhD+ volunteers' donors were processed. Young (Y) RBC and Senescent (Se) RBC were obtained by self-formed gradients of Percoll. The fractionation of the erythrocytes suspensions was demonstrated by statistically significant density-related changes in hematological determinations. Activities of glucose-6-phosphate dehydrogenase (G6PD), of soluble NADH-cytochrome b5 reductase (b5Rs) and membrane-bound b5R (b5Rm) were determined spectrophotometrically. The interaction between monocytes and different RBC suspensions was evaluated by the erythrophagocytosis assay. The G6PD and b5Rm activities in SeRBC were significantly lower than that observed in YRBC. No differences were found in the b5Rs of both groups. We observed an increased rate of erythrophagocytosis the SeRBC compared to YRBC. The decline in the activities of G6PD and b5Rm would indicate a decrease in the antioxidant response associated to RBC aging. These findings would signify that the oxidative changes of membrane occurring during the life span of the RBC might be relevant in the process of removal of SeRBC from the circulation.
authors.affiliation: Laboratorio de Inmunología e Inmunogenética, Departamento de Bioquímica Clínica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina.
authors.forename: Melina Luján
authors.initials: ML
authors.lastname: Brajovich
authors.forename: Angel
authors.initials: A
authors.lastname: Rucci
authors.forename: Irma L
authors.initials: IL
authors.lastname: Acosta
authors.forename: Carlos
authors.initials: C
authors.lastname: Cotorruelo
authors.forename: Silvia
authors.initials: S
authors.lastname: García Borrás
authors.forename: Liliana
authors.initials: L
authors.lastname: Racca
authors.forename: Claudia
authors.initials: C
authors.lastname: Biondi
authors.forename: Amelia
authors.initials: A
authors.lastname: Racca
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D016922:Cellular Senescence / Q000276:immunology / Q000502:physiology; D042966:Cytochrome-B(5) Reductase / Q000378:metabolism; D004912:Erythrocytes / Q000201:enzymology / Q000276:immunology / Q000502:physiology; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism; D006801:Humans; D010587:Phagocytosis / Q000276:immunology / Q000502:physiology
chemical_list: D000975:Antioxidants; D005954:Glucosephosphate Dehydrogenase; D042966:Cytochrome-B(5) Reductase