Fourier-transform infrared spectroscopy: a pharmacotoxicologic tool for in vivo monitoring radical aggression

Among the physico-chemical methods that can be used to investigate induced peroxidation in living cells, Fourier transform infrared (FT-IR) spectroscopy appears to be a valuable technique as it is non-destructive and sensitive for monitoring changes in the vibrational spectra of samples. We examined microsomal fractions from rat liver and brain by FT-IR to study the effect of radical aggression induced in vivo by carbon tetrachloride (CCl4). The length of the acyl chains was increased as a consequence of peroxidation induced by the xenobiotic. Moreover, an enhanced level of cholesterol esters and an increase in phospholipids were observed in the liver and the brain, respectively. The conformational structure of the membrane proteins was changed in both the liver and the brain. In the polysaccharide region, we observed an important loss in glucidic structures, such as a decrease in liver glycogen and in some brain glycolipids. These alterations are probably due to the interactions between cells and CCl4 and the metabolic changes caused by CCl4. Thus, FT-IR spectroscopy appears to be an useful tool and an accurate means for rapidly investigating the in vivo biochemical alterations induced by CCl4 in microsomes, and for correlating them with biochemical and physiological data.