The effect of sulfur dioxide inhalation on visual evoked potentials, antioxidant status, and lipid peroxidation in alloxan-induced diabetic rats.

Abstract

The aim of the study was to investigate the effect of 10 ppm sulfur dioxide (SO(2)) exposure on visual evoked potentials (VEPs), thiobarbituric acid reactive substances (TBARS), and the activities of Cu,Zn superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) in diabetes mellitus. Forty healthy male albino rats, aged 3 months, were divided into four equal groups: control (C), sulfur dioxide + control (CSO(2)), diabetic (D), and sulfur dioxide + diabetic (DSO(2)) groups. Experimental diabetes mellitus was induced by IV injection of alloxane monohydrate in a dose of 50 mg/kg body weight. Ten ppm sulfur dioxide was administered to the animals of sulfur dioxide-exposed groups in an exposure chamber for 1 h/day x 7 days/week x 6 weeks while control and diabetic groups were exposed to filtered air in the same condition. SO(2) exposure, though markedly decreasing retina CAT and GSH-Px activities, significantly increased retina Cu,Zn-SOD activity in the diabetic and nondiabetic groups. In contrast to SO(2)-related increase in the activity of Cu,Zn-SOD, decrease in GSH-Px activity was observed in the brain of those groups. Brain CAT activity was unaltered. SO(2) exposure caused the significant elevation in brain TBARS levels of CSO(2) and DSO(2) groups, whereas only in the retina TBARS level of the CSO(2) group. SO(2) exposure caused the significant prolongations of P(1), N(1), P(2), and P(3) components of VEPs in the nondiabetic and all components of VEPs in the diabetic groups. SO(2) exposure also resulted in significant amplitude reductions in both experimental groups.