Alkane formation during liver microsomal lipid peroxidation

Abstract

During treatment of animals with the hepatotoxin carbon tetrachloride (CCl 4) short-chain alkanes, e.g. ethane and n-pentane, are formed (1–6). It is now generally accepted that these alkanes originate from the decomposition of lipid hydroperoxides (7). However, studies with model compounds demonstrated that metal ions, e.g. iron, are involved in the breakdown of lipid hydroperoxides to alkanes (8, 9). Because we were interested whether metal ions are also involved in CCl 4-induced lipid peroxidation we studied the effect of ferrous ions on CCl 4-induced alkane formation in rat liver microsomes. This could be important, because lipid peroxides are fairly stable in absence of metal ions (10). First of all we had to develop an in vitro system which gives reproducible measurements of alkanes during microsomal incubation. Furthermore, we had to examine whether these alkanes are indeed formed in hepatic microsomes due to CCl 4. On the other hand, we had to find out what the optimal iron concentration in this system would be.