Lymphocyte P- Glycoprotein variability in Healthy individuals

CORTADA C. M., ESCOBAR A., BRAMUGLIA G. F., NISELMAN A.V., CARBALLO M. A., RUBIO M. C.

MEDICINA (BUENOS AIRES)

Fundación Revista Medicina

Lugar: Buenos Aires; Año: 2009 vol. 69 p. 619 - 624

0025-7680

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 A/(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 arid 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 p h a rmaco kinetics and pharrnacodynamics of individualized patients.