The aim of the study was to assess the activity of enzymes in the antioxidant system in the brain of rats subjected to intoxication with sodium fluoride in subtoxic doses.
Methods. The studies were conducted on sexually mature Wistar rats weighing 180-220 g, subjected to oral exposure by means of a probe with aqueous solutions of sodium fluoride (SF) once daily for 60 days at doses of 1/10, 1/100 and 1/1000 DL50, correspondingly, equaling to 20 mg/kg, 2 mg/kg and 0.2 mg/kg of body weight. Chemoluminescent method was used to confirm the induction of free radical processes by measuring the intensity of super-weak luminescence in the homogenate of the liver and the brain in the range of 400-600 nm, which occurs as a result of chemoluminescent reactions. Statistical analysis of the results was carried out using Statistica 6.1 (StatSoft, Inc., USA).
Results. Reducing the intensity of a superweak luminescence on the 60th day of oral administration of SF to rats at a dose of 1/10 DL50 indicates a depletion of the energy potential of the substrate and the inadequate admission of free radicals of biological molecules to the oxidation system. The results showed a significant (p<0.001) increase of chemoluminescence relative to the comparison group of animals in the induced by dual-valent iron ions in the brain of experimental group of rats, who were administered SF at a dose of 1/10 DL50 on the 10th day of observation, on average by 40%.
Conclusion. Under conditions of long-term fluoride intoxication in the rat’s brain, the expressed disruptions of free radical oxidation occur, which is reflected as the increase in the intensity of chemoluminescence of its homogenate and decrease in the activity of the antioxidant enzymes, superoxide dismutase and catalase, in the neocortex, which is a significant factor in the depletion of the adaptive capacity of the body.