title: Oxidation-induced calcium-dependent dehydration of normal human red blood cells.
abstract: Phenazine-methosulphate (PMS) is a strong oxidant that induces reactive oxygen species (ROS) formation in cells. Though it has been shown that PMS increases the red blood cell (RBC) membrane permeability to K(+), the hypotheses on the mechanism of PMS-induced effects are contradictory and there are no data on volume changes induced by this oxidant. Therefore, the influence of the PMS + ascorbate oxidative system on the volume of normal human RBCs was studied. In a Ca(2 + )-containing medium, PMS + ascorbate caused dehydration (shrinking) of RBCs judged by: (1) changes in the density and osmotic resistance distributions of RBCs, and (2) a decrease in their low-angle scattering assessed by FACS analysis. The dehydration resulted from activation of the Gardos channels, was PMS and ascorbate concentration-dependent, was associated with broadening of the density and osmotic resistance distributions of the RBCs, and decreased in the presence of the taxifolin and rutin antioxidants. These findings contribute to a better understanding of the physiology and pathology of oxidatively-modified RBCs and may be of practical significance in estimating the antioxidant activity of various substances.
authors: National Scientific Centre for Hematology, Moscow, Russia. irascher@mail.ru
authors: Irina M
authors: IM
authors: Shcherbachenko
authors: Irina L
authors: IL
authors: Lisovskaya
authors: Vladimir P
authors: VP
authors: Tikhonov
mesh_terms: D000975:Antioxidants / Q000494:pharmacology; D001205:Ascorbic Acid / Q000737:chemistry / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D003681:Dehydration; D004910:Erythrocyte Membrane / Q000378:metabolism*; D004912:Erythrocytes / Q000737:chemistry* / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D008706:Methemoglobin / Q000737:chemistry / Q000378:metabolism; D010084:Oxidation-Reduction
chemical_list: D000975:Antioxidants; D008706:Methemoglobin; D001205:Ascorbic Acid; D002118:Calcium