[Heterogeneity of the cellular sources of restorative processes in vertebrates]

Possible cell sources for restorative processe in adult vertebrates have been considered: (1) differentiated cells undergoing a certain reconstruction after the organ damage; (2) reserve of little-differentiated cells which can be represented by heterogenous populations. Experimental data obtained on a few most studied models of restoration of the damaged organs or their parts have been analyzed. Each particular restorative process can be realized by cell populations which differ from each other by a number of features: origin, potencies, way of formation, localization of cambium, etc. Participation of heterogenous cell populations is most pronounced upon stimulation of restorative processes and in the extreme conditions. Specific involvement of every possible cell source in a particular case of restoration depends on the organism's properties, peculiarities of the damaged organ, as well as on conditions of damage. The existence of diverse cell sources provides for certain reserves of restoration what appears to be indispensable for reliability of restorative processes in varying conditions of damage.