The Gardos channel is responsible for CDNB-induced dense sickle cell formation

The red blood cells (RBCs) derived from blood taken from homozygous sickle cell (SS) patients demonstrate densities that are inversely proportional to the intracellular reduced glutathione (GSH) content. Addition of 1 mM 1-ch loro-2,4-dinitrobenzene (CDNB) to low-density sickle cells (LDSS), at 4 deg rees C, results in a shift of LDSS erythrocytes to high-density sickle cell s (HDSS), with corresponding decreases in GSH, We have previously demonstra ted that this CDNB effect was due to increased K+ leakage and that dense ce ll formation could be inhibited by clotrimazole (specific for the Gardos ch annel) but not DIOA (specific for the K+-Cl- co-transport system) at pH 7.4 (Shartava et al, Am. J. Hematol, 1999;62:19-24), Here we demonstrate that clotrimazole (10 mu M) inhibits dense cell formation at pH 7.1 and 6.8, whi le DIOA (1 mM) has no effect. As pH 6.8 is the optimal pH for the K+-Cl- co -transport system, we can now reasonably conclude that damage to the Gardos channel is responsible for CDNB-induced dense cell formation. (C) 2000 Wil ey-Liss, Inc.