[The regeneration of hematopoietic and connective tissues].

The data are summarized on comparative investigations by the author and co-workers concerning regenerative process in hemopoietic and connective tissues of representatives of molluscs, cyclostomes, fishes and mammals. In gastropods, a regeneration stimulus strikingly increases the volume of amebocyte reproduction foci in the pericardium (primitive organ of hemopoiesis), accelerates the amebocyte yield into the peripheral blood and induces the appearance of DNA-synthesizing cells in the latter. The stimulation of precursor cell reproduction in hemopoietic organs and the acceleration of their maturation and yield into the peripheral blood are common processes in the regeneration response for hemopoietic systems of mammals, fishes and cyclostomes. In contrast to fishes and cyclostomes, adult mammals show the absence of dividing (DNA-synthesizing) cells and mature segmentonuclear granulocytes demonstrate neither RNA nor protein synthesis. In all forms studied, the stromal type cells of hemopoietic nature (fibroblast-like, fixed macrophages, etc.) are a constant and continuously renewed component of connective tissue and play a considerable role in its regeneration.