Content: Quercetin uptake by erythrocytes is rapid. The sodium-hydrogen exchanger (NHE) is a secondary active transporter, regulating intracellular pH, Na(+) concentration and cell volume.
Objective: The aim of present study was to investigate NHE as a function of human age and effect of quercetin on its activity. The NHE activity was correlated with erythrocytes ATPases.
Materials and methods: We analyzed normal, healthy subjects of both sexes (20-82 years). NHE activity was estimated in terms of amiloride-sensitive H+-efflux from acid-loaded cells.
Results: A significant age-dependent increase in NHE activity was observed during aging in humans. Concentration (10(-3 )M to 10(-8 )M)-dependent in vitro treatment with quercetin causes inhibition of NHE activity. The Na(+)/K(+) -ATPase (r = 0.8882) and Ca(2+)-ATPase (r = 0.9540) activities positively correlated with it.
Discussion and conclusion: The present data show an additional mechanism where dietary flavonoids may exerts beneficial effect during aging.
Keywords: Aging; Ca2+-ATPase; Na+/H+ exchanger; Na+/K+ -ATPase; quercetin.