The cellular reaction of kidney after different physical injuries

Autoradiographic investigations on kidney cells were performed after focal cryolesions (-180 to -196 degrees C) and focal heat application (740 degrees C). Cells were studied 12 h to 30 days after the lesions had been produced. In the damage granulation tissue the percentage of radioactively labelled fibroblasts as well as the percentage distribution of leucocytes, monocytes, macrophages, lymphocytes, fibroblasts and fibrocytes and the mean cell concentration were determined. There were no significant differences in the leucocytic and monocytic cell reactions after the two types of physical injuries. However, the percentage of fibroblasts, fibrocytes and macrophages was higher and the percentage of lymphocytes lower after cryonecrosis when compared to heat application. The cell concentration increased during the last 2 weeks of the experimental time after a thermolesion. The labelling index of the wound fibroblasts was significantly higher after the 10th day after thermonecrosis than after in sinus freezing. The increased cellular activity 2 to 4 weeks after heat coagulation of the kidney was probably induced by the delayed resorption of the carbonised necrotic tissue. The reduced phagocytic activity of macrophages might have depended on alteration and modification of molecular cell structures which were different after heat application of freezing. The different lymphocytic reaction seems to be the consequence of different immune responses of the lymphatic system. It is suggested that focal thermolesions may have a stimulatory effect on the cell-mediated immune response and that focal cryonecrosis may induce an increase in humoral immune response.