[Fibroblast-fibroclast: The ultrastructural mechanisms of resorption of collagen fibers in involution of the connective tissue].

Using various experimental models (postpartum involution of the uterus, resolution of a subcutaneous scar which replaced the collagen implant and connective-tissue capsule following the removal of a foreign body) and electron-microscopy and histochemical methods of investigation intra- and extracellular resorption of th e collagenous fibres was extablished. The main role in this process was played by fibroblasts which uncer these conditions could funciton as fibroclasts phagocyting and idgesting in its cytoplasma collagenous fibrillas with the help of lysosomal enzymes. Desintegration of fibroclasts, enriching the medium with these enzymes, stimulated the extracellular lysis of the collagenous fibrillas. This lysis was particularly intensive in the presence of an inflammatory process, and even could take place before the intracellular resorption. In macrophages no intracellular lysis was observed, however, they could phagocyte denaturated collagen, deprived of structural orgainzation.