[Permeability of the erythrocyte membrane to pentoxifylline and propentofylline. Research on their effects on some structural and functional properties of the membrane].

Contrarily to previous studies, we show that the red blood cell membrane is permeable to pentoxifylline and propentofylline. The kinetics of inward and outward flux are rapid. Both molecules do not transit via the pores for the water transport but instead seems to freely diffuse through the lipidic bilayer. It has not been possible to detect a significant compartimentation of the two drugs on the erythrocyte membrane. We have been searching for a possible modification of some of the structural and functional properties of the erythrocyte membrane in the presence of pentoxifylline and propentofylline. The experiments included measurement of the membrane fluidity, kinetics of water, glycerol and ethylene glycol transport, and studies on the stability of the membrane-cytoskeleton complex. No detectable differences were measured suggesting that the therapeutic action of pentoxifylline and propentofylline may result more from protective effect in the cases of pathological stresses occurring on the erythrocyte membrane than from their ability to repair the damaged membrane.