Fig. 1

Development of Walker 256 carcinoma cells induced bone pain. a–d Histology of tibia bone destruction stained by H&E. a Bone from normal rats; b bone injected with PBS; c, d showing tumor growth and bone destruction after Walker 256 injection at day 12 (c) and day 16 (d) (tumor cells are marked by hollow arrows). e Showing the development of mechanical allodynia to von Frey hair stimulation in normal, Walker 256 or PBS-inoculated rats. Data are expressed as means ± SEM. *P < 0.05 versus PBS inoculated rats