title: The Gardos channel is responsible for CDNB-induced dense sickle cell formation.
abstract: 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-chloro-2,4-dinitrobenzene (CDNB) to low-density sickle cells (LDSS), at 4 degrees C, results in a shift of LDSS erythrocytes to high-density sickle cells (HDSS), with corresponding decreases in GSH. We have previously demonstrated that this CDNB effect was due to increased K(+) leakage and that dense cell formation could be inhibited by clotrimazole (specific for the Gardos channel) 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 microM) inhibits dense cell formation at pH 7.1 and 6.8, while 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.
authors.affiliation: Department of Structural and Cellular Biology, University of South Alabama, College of Medicine, Mobile 36688, USA.
authors.forename: A
authors.initials: A
authors.lastname: Shartava
authors.forename: J
authors.initials: J
authors.lastname: McIntyre
authors.forename: A K
authors.initials: AK
authors.lastname: Shah
authors.forename: S R
authors.initials: SR
authors.lastname: Goodman
mesh_terms: D000755:Anemia, Sickle Cell / Q000139:chemically induced* / Q000473:pathology*; D003022:Clotrimazole / Q000494:pharmacology; D004137:Dinitrochlorobenzene / Q000494:pharmacology*; D005978:Glutathione / Q000097:blood; D006131:Growth Inhibitors / Q000494:pharmacology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D015221:Potassium Channels / Q000502:physiology*
chemical_list: D004137:Dinitrochlorobenzene; D006131:Growth Inhibitors; D015221:Potassium Channels; D003022:Clotrimazole; D005978:Glutathione