Enzymatic production of hydroperoxides of unsaturated fatty acids by injury of mammalian cells.

Hydroperoxides of unsaturated fatty acids (LOOHs) are generated by homogenisation of liver tissue, but not if the liver is boiled before homogenisation. This observation indicates that the LOOHs are produced in an enzymatic reaction. This assumption is corroborated by an analysis of the reduction products of LOOHs by gas chromatography/mass spectrometry (GC/MS). A main part of LOOHs is derived from linoleic acid and not from arachidonic acid. Massive cell damage occurs by myocardial infarction or other severe injuries; these events were found to be connected with generation of LOOHs. We suspect--considering the above outlined experiment--that the LOOH production is also mainly caused in these cases by activation of enzymes and not--as postulated--by an autocatalytic process. Increased amounts of LOOHs are found in many chronic diseases, e.g. in rheuma, atherosclerosis or psoriasis, obviously caused by a gradual damage of cells. Thus, the common root of an increased LOOH level might be cell injury.