Physical exercise may improve macrophage phagocytic activity of tumor bearing mice.

The influence of an endurance training on the phagocytic activity of macrophages from tumor bearing mice was studied. Female NMRI mice were trained on a treadmill. The training period differed from 3 to 6 weeks for different experimental groups and was performed either before or after tumor inoculation, or both. Either L-1210 or S-180 tumor cells were inoculated into the peritoneal cavity or the interscapular region, respectively. The phagocytic activity of peritoneal and spleen macrophages was estimated at different intervals. The trained animals' macrophages showed increased phagocytic activity especially evident in the group that had been trained before and after tumor inoculation. It was concluded that physical exercise might enhance phagocytosis of macrophages in tumor bearing animals and that this effect strongly depends on the duration and onset of the training program.