The effects of the B16 malignant melanoma on induced inflammatory responses in host mice: Inhibition of macrophage exudation

Abstract

C57BL6 mice were injected with B16F1 or B16F10 cells and granulocyteor macrophage-rich inflammatory responses were subsequently induced. Analysis of cell yields showed that the percentages of macrophages in the inflammatory exudates of tumour-bearing animals were significantly depressed. No significant changes were noted, however, in the levels of granulocytes in peritoneal exudates from tumour-bearing mice when compared to appropriate controls. In parallel studies, the levels of resident macrophages and granulocytes following lavage of non-stimulated peritoneal cavities of mice with and without tumours were monitored as were the levels of blood monocytes and leukocytes. No consistently significant changes were noted in the levels of blood leukocytes or monocytes in normal or tumour-bearing animals. Further-more, no consistently significant changes were found in the percentages of granulocytes normally resident in the peritoneal cavities of mice with or without the B16 melanoma. It was found, however, that the percentages of resident macrophages in mice bearing the B16 malignant melanoma were significantly depressed relative to those found in normal animals.