1 KINETIC MODELLING OF IN VITRO LIPID PEROXIDATION EXPERIMENTS -- "LOW LEVEL" VALIDATION OF A MODEL OF IN VIVO LIPID PEROXIDATION ARMINDO SALVADOR # *, FERNANDO ANTUNES # AND RUY E. PINTO #,@ # Grupo de Bioquímica e Biologia Teóricas, Instituto de Investigação Científica Bento da Rocha Cabral, Cç. Bento da Rocha Cabral, 14, P-1200 LISBOA, PORTUGAL and @ Departamento de Química e Bioquímica da Faculdade de Ciências da Universidade de Lisboa, R. Ernesto de Vasconcelos, Edifício C1, 5º piso, P-1700 LISBOA, PORTUGAL Running title: Kinetic modelling of lipid peroxidation ABSTRACT: Kinetic modelling overcomes some of the drawbacks of purely intuitive thinking in integrating information accumulated on chemical reactions involved in oxidative stress. However, it is important to assess if current knowledge about the reactions that mediate lipid peroxidation already allows satisfactory modelling of this process in near-to-physiological conditions. In this paper, a set of increasingly complex in vitro experiments on antioxidants (α-tocopherol and ascorbate) and lipid peroxidation in heterogeneous systems is simulated. Quantitative to semiquantitative agreement is found between experimental and simulation results. In addition, this theoretical analysis provided useful insights, suggested new hypotheses and experiments and pointed out relevant aspects needing further research. The results encourage and serve as partial validation for the formulation of relatively detailed mathematical models of in vivo lipid peroxidation. Some important aspects of the formulation and analysis of such models are discussed. Keywords: oxidative stress, antioxidants, α-tocopherol, ascorbate, free radicals, computer simulation. * Author for correspondence