The Significance of Pentane Measurements in Man

Abstract

Lipoperoxidation of polyunsaturated fatty acids, constituents of cell membranes, is the main feature running out of in vitro experiments on oxygen toxicity (1). Theoretical considerations let us suppose that, in in vivo conditions, lipid autoxidation can occur, explaining some aspects of oxygen toxicity, particularly at the pulmonary level (2). However, until now, no absolutely safe methods have been elaborated, to unequivocally demonstrate the in vivo lipoperoxides production. Theoretically, a safe method would determine a lipoperoxide derivating product which is not further catabolized and which arises exclusively from lipoperoxidative pathway. Different procedures were proposed, each one based on the determination of a particular step, during hydroperoxide decomposition. The steps are the following:

• a) Peroxidation of polyunsaturated fatty acids, after diene conjugation (3);

• b) Spontaneous or catalytically accelerated breakdown of hydroperoxides leading to malonaldehyde (MDA) and to other fragments, which become finally hydrocarbons, such as ethane and pentane, or pentanol (4,5).