[Quantitative and qualitative cellular changes in the vertebral disks in ontogeny].

The author has obtained data concerning an average number of the cellular elements in the vertebral discs and the peculiarities of ultraorganization of their tissue cells using the methods of morphometric and electron microscope analysis of the LIV-V vertebral discs taken from 66 human cadavers (accidental deaths) as well as from 80 rabbits, 12 dogs from the last stages of embryogenesis to extreme old age and from some other Mammalia of various age groups. It has been demonstrated that in the persons aged 45-65 there was a reliable reduction in the quantity of the cells in the vertebral discs. Part of the preserved cellular elements considerably reduced their secretory activity. These processes together with other factors may serve as the basis for the development of osteochondrosis of the spinal column in the people during the second part of their life. In the animals whose specific longevity and body mass are not so high such changes in the vertebral discs are less significant.