Relation of tumor-associated macrophages to
tumor neovascularization in murine transplanted
tumor,
sarcoma 180(S180), was quantitatively analysed in situ on days 3, 6 and 9 after
tumor implantation. Infiltrating macrophages in
tumor were identified in
paraffin section by
alpha-naphthyl butyrate esterase stain and subdivided by electron microscopy according to the
peroxidase activity. Simultaneously, the structure of newly formed microvessels was quantitated under light microscope by stereological morphometry. The results showed that, as the
tumor grew and blood vessels proliferated, the number of infiltrating macrophages in
tumor increased obviously but the ratio of
peroxidase (PO) positive mononuclear phagocytes tended to decrease in contrast to the increase of PO-negative phagocytes. Microvasculature volume was found to be positively correlated to the proportion of PO-negative macrophages but negatively correlated to the proportion of PO-positive mononuclear phagocytes. It was indicated that
tumor angiogenesis was related to the mature macrophages in the
tumor.