Age-related changes of the multidrug resistance P-glycoprotein function in normal human peripheral blood T lymphocytes

• Main Authors: C.G. Machado, R.T. Calado, A.B. Garcia, R.P. Falcão
• Format: Article
• Language: English
• Published: Associação Brasileira de Divulgação Científica 2003-12-01
• Series: Brazilian Journal of Medical and Biological Research
• Subjects: P-glycoprotein; Multidrug resistance; Lymphocytes; Rhodamine 123; Flow cytometry
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2003001200006

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.