Indices of oxidative stress under intranasal administration of deicing reagent solutions in rats

Abstract

Introduction. The use of road deicing reagents (RDR) is an effective measure to reduce winter traumatism and requires enhancement of methods for evaluation of deicers safety. The aim of investigation: to study markers of oxidative stress in rat blood samples during intranasal (i/n) administration of RDR solutions, as a model of intake under natural conditions, using liquid commercial RDR (22% CaCl2; 6% NaCl). Material and methods. Male Wistar rats (10 rats per group) were daily injected into the nasal cavity with 100 μl of RDR solutions in concentrations (C) 0; 0.75; 7.5 and 75 ml per liter of tap water. 5 and 28 days after the start of the experiment, the content of malondialdehyde (MDA), GSH, the activity of SOD, catalase, glutathione peroxidase (GPO) and glutathione reductase (GR) in the hemolysates were determined. Logarithmic transformation x=lg(C+0.01)+2 was used for regression analysis of dose - effect relations. Results. 5 days after the start of the experiment, adaptive dose-dependent changes in activities of SOD (R = -0.504; p=0.001); GR (R = 0.548; p<0,001) and catalase (R=0.725; p<0,001) were revealed, and after 28 days these effects were replaced by dose-dependent increase in MDA content (R=0.617; p<0,001) and GPO activity (R=0.326; p=0.04). The revealed effects, apparently, are due to the presence of additional RDR components (such as detergents, corrosion inhibitors, etc.), since significant differences with corresponding control groups were found also during administration of 0.75 ml RDR per liter (CNa+ 200 times lower than in saline solution; CCa2+ equivalent to its serum content). In particular, sharp increase in catalase activity after 5 days may be indirect evidence of anticorrosive formates metabolism (commonly used anti-corrosive additive) in the conditions of their entry bypassing the portal vein. Conclusion. I/n administration of the studied RDR solutions (0.75-75 ml/L) gave distinct dose-dependent signs of compensated (5 days) and decompensated (28 days) oxidative stress, presumably due to the presence of additional components besides of basic chlorides.