Figure 4: Metalloproteinase activity in BOOP tissues. The gelatin zymography revealed MMPs activity from three representative BOOP and normal pigs (a). For each individual BOOP or normal pig, six sample lung sections were evaluated for MMP activity and averaged. Then, the averages from the BOOP and normal animals were pooled from the five different pigs to generate the data presented (b). The activities of proMMP-9, MMP-9, proMMP-2, and MMP-2 were all significantly increased in BOOP group ((b), ). versus normal group (, six replicates in each individual pig).