Pirfenidone regulated chemokine production in the lungs of bleomycin (BLM)-treated mice. Chemokine (CC motif) ligand-2 (CCL2), CCL12, and chemokine (CXC) ligand-12 (CXCL12) in lung digests were measured with enzyme-linked immunosorbent assay on day 14 of BLM treatment. (A) CCL2 production was significantly increased in BLM-treated mice compared with that in saline- and pirfenidone-treated mice. Pirfenidone significantly attenuated the production of CCL2 in BLM-treated mice (P = 0.0003). (B) CCL12 production was also significantly stimulated by BLM treatment, and pirfenidone administration significantly attenuated this increase (P < 0.0001). (C) CXCL12 production was increased in BLM-treated mice compared with that in saline-treated mice. Although a trend toward attenuation of CXCL12 production by pirfenidone treatment was found, statistical significance was not reached. The level of each chemokine in the supernatant of the lung homogenate was standardised with the wet weight (g) of each lung. PFD, pirfenidone.