INTRODUCTORY LECTURE: THE HISTORY OF REDOX BIOLOGY, FROM « REDUKTONE » OF HANS VON EULER TO FREE RADICALS EXAMPLIFIED BY THE MAILLARD REACTION, THE ELASTIN RECEPTOR AND ATHEROGENESIS

Redox processes play an important role in Biochemistry but they are also involved in the generation of a variety of pathologies. Organic chemists as Hans von Euler realised the importance of redox processes. He described strongly reducing molecules called « reduktones » and « reduktonates » examplified by Triose reduktone and also ascorbic acid discovered at about the same time by Szent-Gyorgyi. The possibility and importance of single electron transfer creating Free Radicals did not penetrate organic chemistry at the same time although discovered by physical chemists in the late years of the XIXth century, one example is the Fenton reaction (1894) and the Maillard reaction (1912). To a large part, the chemistry and biology of redox processes are based on the exceptional properties of oxygen which will be reviewed. The age-dependent increase of vascular pathology is also an example which will be discussed. The degradation of Elastin liberates elastin peptides which activate the elastin receptor with release of elastases and Free Radicals. Elastin peptides produce oxidative burst on monocytes with Free Radical release and apoptotic cell death. The presence of the Elastin receptor on fibroblasts and smooth muscle cells further confirms the importance of these processes in age-related vascular pathologies.