Unsaturated lipids and intestinal bacteria as sources of endogenous production of ethene and ethylene oxide.

Studies of adducts to hemoglobin (Hb) have revealed levels of hydroxyethylations of i.a. N-terminus (valines) in knowingly unexposed animals and persons (non-smokers). This paper describes some exploratory experiments with mice, carried out with the aim of tracing the origin of these background levels. It is shown that the hydroxyethylvaline content in Hb is higher in animals fed unsaturated lipids and lower in bacterium-free as compared to control animals. Lipid peroxidation and metabolism of intestinal bacteria, giving rise to ethene, precursor of ethylene oxide, are thus indicated to be sources of observed background hydroxyethylations.