Morphological studies of the Kupffer cells in tumor-bearing hosts through the silver impregnation.

Abstract

Morphological changes of the metallophil Kupffer cells, stained by the silver impregnation, have been investigated on autopsy eases with malignancy and on rats with Yoshida sarcoma. Yoshida sarcoma cells were injected into the subcutis, liver, portal vein and spleen of the rats. In the autopsy cases with malignancy, Kupffer cells were numerically increased and hypertrophic. These changes were always observed, even if the malignancy existed in any other organs except the liver. In the rats, Kupffer cells were increased in number and became hypertrophic after transplantation or in accordance with growth of the tumor. The acid and the alkaline phosphatases and the non-specific esterase became more active. The PAS reaction was also rather intensive. The most marked changes of Kupffer cells were seen in cases of the intrasplenic transplantation of tumor cells. The vital staining showed a depressed phagocytic activity in contrast with enzymatic and PAS reactivities. It has been suggested through the present study that Kupffer cells of the reticuloendothelial system act against the growth of malignant tumors.