The review, consider the basic laws of interaction of elements in real physiological conditions of metabolism. The law of replacement and two it consequences have ben formulated taking into account a major principle of cybernetics - the feedback principle. A rule of a fractional threshold and the law of toxicity based on the Mertz`s rules have been formulated. These laws have been used here for understanding of mechanisms of occurrence and development of apoptosis and also side-effects of statins.Study of bioinorganic mechanisms of different diseases is perspective way for search of complex connections of metals and ligands, capable to interaction with initiators of chain reactions, and for a finding of substances - inhibitors these reactions.
Keywords: the law of replacement, consequence of the law of replacement, rule of fractional threshold, apoptosis, statins, chain reaction