The wound healing of the liver after thermonecrosis. Autoradiographical investigations with 3H-thymidine on rats.

Histological and autoradiographical studies were performed on the liver of rats after local thermonecrosis. The results were compared with those after local cryonecrosis. After thermocoagulation (740 degrees C/4 sec) each animal received an i.p. injection of 3H-TdR (2.5 micronC/1 g body weight). The survival times ranged from 12 hours to 30 days. In the HE stained histological slides the morphological changes and the percentages of the cells in the granulation tissue and in the stripping film autoradiograms the percentages of radioactively labeled fibroblasts and hepatocytes were determined. After 12--24 hours the thermonecrosis is complete with leucocytic demarcations. Five days later widespread granulation tissue develops in the marginal zone of the necrosis. 20 to 30 days after thermocoagulation small necrotic parts are still seen in the center sorrounded by a fibrous scar. Autoradiographically the highest percentages of labeled epithelial and mesenchymal cells are observed between the second and the third postoperative day. Four weeks after thermonecrosis there are still increased cellular proliferative activities. Therefore, it can be stated that the inflammatory resorptive woundhealing processes following thermonecrosis in the liver are maintained much longer than after other physical injuries especially after cryonecrosis.