Artemin suppressed nocifensive behaviors induced by formalin. Artemin (10 μg/ml) or PBS was pre-treated subcutaneously 5 min before formalin (3% in 50 μl saline) injection. Time course (A) and cumulative data (B) of the number of hind paw flinches after formalin injection with artemin or PBS pre-treatment were measured. The number counted per 5 min interval in the initial 1 h post-injection period in A. B shows cumulative number of paw flinches during the Phase I (0-5 min) and the second Phase II (10-60 min) after injection of formalin. * p < 0.05; ** p < 0.01; *** p < 0.0005; **** p < 0.0001 versus PBS + formalin (unpaired t-test), # p < 0.001; versus PBS + formalin (two-way repeated ANOVA followed by Fisher's PLSD), $ p < 0.005; $$ p < 0.0001 versus PBS + formalin (two-way factorial ANOVA). Numbers in parentheses indicate number of rats used in each group.