title: Lymphocyte P-glycoprotein variability in healthy individuals.
abstract: The aim of the present work was to describe the distribution of lymphocyte P-glycoprotein activity on a population of healthy individuals, taking also into account sex and age. P-glycoprotein activity in lymphocytes was measured by the Rhodamine 123 efflux assay using flow cytometry, in the presence and absence of verapamil, a P-glycoprotein inhibitor. We obtained a range of P-glycoprotein activity from 1.04 to 3.79. The distribution of the activity in the population studied was better described by a bimodal model, according with the Kolmogorov-Smirnov test. The frequency adjusted to the following equation: F = 0.70 N (2.11; 0.43) + 0.30 N(3.29; 0.26), in which 0.70 and 0.30 represented the proportion of each group, and 0.43 and 0.26 were the standard deviations of the activity of each group, respectively. The study of the relationship between subjects' age and P-glycoprotein activity showed no statistical significance. When healthy volunteers were separated according to sex, similar distributions were observed, although for men an increase in proportion of higher P-glycoprotein function group was observed. The variability observed in the population studied was important, with some volunteers with very scarce activity and some with a fourfold higher activity. Characterization of P-glycoprotein functionality in the population represents a useful contribution to the beginning of pharmacological treatments that consider its effect on pharmacokinetics and pharmacodynamics of individualized patients.
authors.affiliation: CIGETOX, Citogenética Humana y Genética Toxicológica, Departamento de Bioquímica Clínica, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Argentina.
authors.forename: Catalina M
authors.initials: CM
authors.lastname: Cortada
authors.forename: Anahi
authors.initials: A
authors.lastname: Escobar
authors.forename: Guillermo F
authors.initials: GF
authors.lastname: Bramuglia
authors.forename: A Viviana
authors.initials: AV
authors.lastname: Niselman
authors.forename: Marta A
authors.initials: MA
authors.lastname: Carballo
authors.forename: Modesto C
authors.initials: MC
authors.lastname: Rubio
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism*; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001118:Argentina; D018432:Drug Resistance, Multiple / Q000502:physiology*; D005260:Female; D005456:Fluorescent Dyes; D006801:Humans; D008214:Lymphocytes / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D020112:Rhodamine 123; D017678:Sex Distribution; D012737:Sex Factors; D044465:White People; D055815:Young Adult
chemical_list: C513055:ABCB1 protein, human; D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D005456:Fluorescent Dyes; D020112:Rhodamine 123