title: Age-related changes of the multidrug resistance P-glycoprotein function in normal human peripheral blood T lymphocytes.
abstract: The multidrug resistance P-glycoprotein is a transmembrane efflux pump expressed by lymphocytes and is involved in their cytolytic activity. In the present study, we investigated the age-related changes of P-glycoprotein function in normal peripheral blood lymphocytes. Blood samples from 90 normal volunteers (age range, 0 to 86 years) were analyzed. P-glycoprotein function was assessed by the flow cytometric rhodamine 123 assay. P-glycoprotein function was highest in cord blood and progressively declined with age in peripheral blood T CD4+ and CD8+ cells. In contrast, P-glycoprotein function did not vary with age in CD19+ B or CD16+CD56+ natural killer cells. These data suggest that the decline in P-glycoprotein function in T CD4+ and CD8+ lymphocytes as a function of age may contribute to the decrease in T cell cytolytic activity with aging.
authors.affiliation: Centro de Terapia Celular, Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil.
authors.forename: C G
authors.initials: CG
authors.lastname: Machado
authors.forename: R T
authors.initials: RT
authors.lastname: Calado
authors.forename: A B
authors.initials: AB
authors.lastname: Garcia
authors.forename: R P
authors.initials: RP
authors.lastname: Falcão
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000502:physiology*; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D018432:Drug Resistance, Multiple / Q000502:physiology*; D005434:Flow Cytometry; D005456:Fluorescent Dyes; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007694:Killer Cells, Natural / Q000502:physiology; D008875:Middle Aged; D020112:Rhodamine 123; D013234:Stem Cells / Q000502:physiology; D013601:T-Lymphocytes / Q000502:physiology*
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D005456:Fluorescent Dyes; D020112:Rhodamine 123