[Role of animal experimentation in pharmacology and toxicology]

Animal experiments are scientifically justified to establish kinetic parameters of xenobiotics in vivo (absorption, diffusion, biotransformation, elimination of pesticides, food additives and drugs). They are indispensable for evaluating toxic effects which appear with delay (carcinogenesis, drug dependence), and for exploring reactions which involve complex regulating systems in the whole organism. In this field, methods are in progress, leading to use less and less animals and to obtain more accurate data. Some problems still exist concerning painful experiments and controls of local tolerance. In vitro assays must not be opposed against those performed in vivo, since both are complementary and must be coordinated in order to make fruitful progresses for the benefit of men but also of animals.