Rheological action of bepridil on normal and sickle erythrocytes

Abstract

Bepridil is a new calcium antagonist that was found to cause swelling and stomatocytosis of normal erythrocytes by increasing passive permeability of cations across the cell membrane. At 100 µmol/l, the drug also fully inhibited the Ca²⁺-activated (Gardos) K⁺ channel. When normal and sickle erythrocytes were dehydrated by Ca²⁺ loading using the ionophore A23187, bepridil at 10–100 µmol/l had a significant protective effect against loss of filterability through pores of 5 µm diameter. Bepridil has the potential to prevent erythrocyte dehydration and sickling by blocking entry of Ca²⁺, by inhibiting loss of K⁺ via the Gardos channel, and by increasing passive permeability of cations from plasma.