[Hormonal imprinting--the unforeseeable future]

Hormonal imprinting takes place at the first encounter between the developing receptor and the target hormone, perinatally, causing life-long changes in the binding capacity of the receptor and the indexes influenced by it. Perinatal hormonal imprinting is absolutely needed for the maturation of receptor, however, at the same time, molecules similar to the target hormone (related hormones, synthetic drugs acting at receptor level, chemicals, environmental pollutants etc.) can cause faulty imprinting, also with (morphological, biochemical, receptorial, behavioral) consequences for life. Although imprinting is characteristic and inevitable perinatally, it can be provoked in any period of life in developing cells, especially at the weanling and adolescent age (late imprinting). There is no gene mutation during imprinting, however, the methylation pattern of the genes changes and that inherits epigenetically the imprinting, which is manifested in disposition to diseases or in diseases (e.g. tumor formation, metabolic syndrome). Imprinting is inherited between generations that could cause--in the present chemical world--evolutionary consequences. Thus, medicaments or preventive drugs, e.g. pregnancy protecting drugs or oral contraceptive pills should be given cautiously, especially in the critical periods, considering that consequences are manifested always after a long period (sometimes decades) or in the next generations.