DIURNAL RHYTHM OF CARBON TETRACHLORIDE HEPATOTOXICITY IF A LIGHT SYNCHRONIZER IS CHANGED UNNATURALLY

The experiments were carried out on 72 white male rodents weighing 150-220 g with ad libitum diet during the light and dark periods. These periods were striped in the ratio of 12:12. The toxic damage of liver was caused during the various day periods (at 6am, 10am, 2pm, 6pm, 10pm and 2am) by the intramuscular injection of CCl4 solution at a dose of 0.5 ml per 100 g body weight. The samples were gathered in 24 hours after the injection of CCl4. It was pointed that the most significant hepatotoxic influence of CCl4 was at 6pm and 10pm. Perhaps, it is connected to large amount of enzymes contained in the membrane, such as cytochrome P450-3A?reductase and succinate dehydrogenase. The low level of diene conjugates was observed during this period of time, which was the evidence for more serious damages and disruption of the endoplasmic reticulum membranes. Later these membranes were slightly able to metabolize CCl4 to active radicals, which normally induce lipid peroxidation. The significant increase of malondialdehyde level was measured on a background of these conditions. It can be considered as the result of antioxidant system activity exhaustion.