Estimation of macrophage IL-10 and NO secretion in the cytotoxicity against transplantable melanomas in relation to the progression of these tumours.

The relationship between the secretion of interleukin 10 (IL-10) and nitric oxide (NO) by hamster peritoneal macrophages and their cytotoxic effects on the cells of those two melanoma lines was studied. The nonuniform reaction of macrophages from hamsters bearing two transplantable melanoma lines has been observed. An increase in the cytotoxicity of macrophages from hamsters bearing the amelanotic melanoma line was accompanied by an inverse correlation between IL-10 and NO secretion. Such a relationship was not found in the case of macrophages from animals bearing the native-melanotic melanoma line. It is suggested that the phenotypical changes of melanomas connected with their progression modified the cytotoxic and secretory activity of the macrophages with regard to IL-10 and NO.