[Theoretical and applied aspects of experimental teratology]

The dependence of teratogenic effect from the agent specific properties, dose and exposition and the genotype of embryo and maternal organism is considered. The stage specificity of teratogens and the concepts of critical developmental periods are analyzed. The data on general mechanisms of embryonic defects related to the mutations and their phenocopies induced by teratogens are evaluated. The applied aspects of experimental teratology and, in particular, the testing of drugs' teratogenicity and the development of mathodical bases for the establishment of teratogens among the chemical pollutions are intimately connected with and depend on more profound studies of the theoretical bases of teratology. A new method of testing the chemical substances is proposed: search for embryotoxic and teratogenic factors in the blood of animals which were in contact with teratogens. With this aim the cleaving postimplantation mouse and rat embryos are cultivated in the medium with the blood serum from the animals treated with teratogens. This allows to detect in the blood not only the substance in question, but also the toxic products of its metabolism and the toxic substances formed in the maternal organism under the effect of this teratogen. The approaches to the express methods of estimation of teratogenicity are evaluated and the grounds of many steps testing the chemical polutions for teratogenicity are provided.