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.