[Changes of structure and function of spleen macrophages induced by malignant neoplasia].

Spleen macrophages, as most active elements of the mononuclear phagocyte system, were studied using light and electron microscopy in experimental rats and mice with differenet types of malignant neoplasia, including chemically induced carcinogenesis, transplantable tumor growth and in leukosis. In chemically induced carcinogenesis macrophage phagocytic activity was reduced, morphologically, the cellular surface smoothing, cytoplasm organell reduction and nuclear pyknotic changes were found. In animals with transplanted tumors, high activity of spleen macrophages was detected. In animals with leukosis, macrophages are characterized by reduced phagocytic activity, smoothed cellular surface and a variable number of lysosomes. The results obtained support the concept of high reactivity of the cells of mononuclear phagocyte system in neoplasia.