Cytochemical study of activated peritoneal macrophages in normal and tumor-bearing rats

Enzyme characteristics of in vitro activated peritoneal macrophages of normal and BP6-TU2 tumor-bearing rats were compared with those of nonactivated macrophages. The activating effect of LPS, IFN-gamma, IL-2, TPA, TNF and Zymosan was assessed by the determination of the activities of alpha-naphthyl butyrate esterase (ANBE), tartrate-resistant acid phosphatase (TRAP), beta glucuronidase (BG) and 5'nucleotidase (5'NT). The used individual activators induced the macrophage enzyme activities in different degrees. LPS, TPA and TNF appeared to be the most effective activators of enzyme activities in macrophages of normal rats. IFN-gamma, IL-2 and Zymosan were less effective. The macrophages of BP6-TU2 tumor-bearing rats were less sensitive to the stimulatory effect of activators with respect to their enzyme activation capacity, except for TRAP activity. The results indicate that enzyme ANBE is an adequate marker of rat peritoneal macrophages. Enzyme TRAP determines the macrophage activation degree more expressively, in comparison with BG and 5'NT. The differences in enzyme activities could be a suitable marker of macrophage activation and might suggest the dependence on the pathway of macrophage stimulation by distinct activators.