[Reliability of enzyme systems and molecular mechanisms of aging].

A stochastic model of animal mortality and ageing is proposed. In a living being there is a "biological clock", constructed from Q kinds of functional elements (genes), The reliability of functioning of these genes determines the biological age of the being. Oxidative processes in the cells are accompanied by random failures of electron transfer enzyme systems, which result in appearance of free superoxide radicals. Failures of electron transfer enzymes and of defence enzymes lead to accumulation of functional damages in the genes of the "clock". In terms of the model experimental data of gerontology (Gompertz's law, Strehler-Mildvan's compensation effect, etc) are easily explained. The value of Q for the man is estimated to be of the order of 10. Some possible mechanisms of action of "geroprotectors" have been discussed.