THE SEASONAL VARIATIONS OF CARBON TETRACHLORIDE TOXICITY

Abstract

Biological rhythms are genetically fixed as a universal form of adaptation to cyclically changing environmental factors. Many organs including the liver and body systems function in an oscillatory mode. Its central role in the process of detoxification may determine the variability of toxic effects in the metabolism of xenobiotics. The including of chronobiological patterns in the procedures of toxicological and hygienic studies will allow more accurate assessing of the properties of tested substances. The aim of the study was to identify variations in the seasonal chrono-reactivity of warm-blooded animals to the hepatotoxic effects of carbon tetrachloride. In studies there were used Wistar rats, divided into experimental (CCl4-induced toxic hepatitis) and control groups in the winter, spring, summer, and autumn. Standard laboratory diagnostic methods studied key indices characterizing the functional activity of the liver and the antioxidant status of the organism (direct and total bilirubin, cholesterol, alkaline phosphatase, ALAT, ASAT, hydroperoxide, malonic dialdehyde, catalase in the liver tissues). According to the results of the conducted research, seasonal biorhythms have a modulating effect on the organism of warm-blooded animals, and the amplitude of the detected fluctuations was observed to be wider in terms of modeled pathology. The calculation of the variation values of numerical indices shows fluctuations to take place in the range of 10-60% in control group, and within the range of 60-300% in the pathology. The most labile index was catalase. Since the mechanism of carbon tetrachloride toxicity is mediated through the initiation of lipid peroxidation, this may explain the observed phenomena of seasonal chronoreactivity. Thus, taking into account the modulating role of biorhythms in protocols for toxicity testing can optimize the currently used procedures of human health risk assessment.