[The ultrastructure of the cellular elements of granulation tissue]

Electron-microscopy studies of the granulation tissue cells in an experimental wound in mice during one week after its infliction were carried out. Twenty four hours following the trauma neutrophilic leucocytes were found to be predominant in the wound. Disintegrating, they were utilized by macrophages, the latter being numerous in the granulation tissue on the 2nd-3rd day. Their protoplasm was found to contain multitude of various vacuoles and inclusions, which testified to a high phagocytic activity of these cells, whose main function in the wound process is purification of the wound. Evolution of the ultrastructural changes in fibroblasts of the granulation tissue was followed up. On the 5th-7th day they showed a pronounced hyperplasia of the granulation endoplasmic reticulum and an increased number of ribosomes. These changes in fibroblasts reflect their high synthetic activity and represent a structural base of the intensive collagenformation.