Activation of red blood cell glutathione peroxidase and morphological transformation of erythrocytes under the action of tert-butyl hydroperoxide.

Abstract

Susceptibility of control and diabetic erythrocytes to oxidative stress was measured after incubation with various concentration of tert-butyl hydroperoxide (t-BHP). TBA-reactive substances (TBARS) formed were determined by the method of Stocks & Dormady modified by Jain. GSH and total glutathione were estimated by the procedure of Ellman and Akerboom and Sies. Activity of GSH peroxidase was determined by the method of Martinez et al. Protein SH groups were determined after membrane isolation by the method of Dodge et al. Cell morphology was viewed under phase contrast microscope with a magnification of 500x. All results were analyzed by the unpaired two tailed Student's t-test. Oxidative treatment of erythrocytes with tert-butyl hydroperoxide significantly increases the reaction rate but decreases the affinity for substrate (tert-butyl hydroperoxide). The susceptibility of the enzyme from diabetic erythrocytes to oxidation is higher in comparison with normal cells. The oxidation of cellular reduced glutathione (GSH) is not correlated with oxidation of membranous protein SH-groups. Oxidative damage of erythrocytes induces significant cell morphological transformations.