Carbon tetrachloride, bromotrichloromethane and ethanol acute intoxication. New chemical evidence for lipid peroxidation in rat tissue microsomes

Abstract

Second-derivative spectroscopy was used to determine the conjugated-diene shift that measures the extent of the first step of lipid peroxidation after carbon tetrachloride (CCl4), bromotrichloromethane (BrCCl3) and ethanol intoxication. The conjugated-diene signal was recorded in the second-derivative spectra as a minimum peak at 233 nm. The use of this method enabled us to show that, under our experimental conditions, CCl4- and BrCCl3-dependent conjugated-diene formation in rat liver microsomes is not dose-dependent and increases linearly with time up to 3h. Proportionality was not obtained between the second-derivative-spectroscopy method, and the thiobarbituric acid and difference-spectra methods. In addition, whereas the thiobarbituric acid and difference-spectra methods gave positive results at zero time, second-derivative spectroscopy showed no evidence of formation of conjugated dienes under the same experimental conditions. Intoxication with ethanol was shown by the appearance of the conjugated-diene signal in liver microsomes 24 h after the administration of the toxin. Intoxication with either of the haloalkanes or ethanol did not give rise to any similar peak in lung and brain microsomes. The results obtained are discussed.