Figure 5.

Macrophage-mediated lung fibroblast collagenase-3 induction is dependent on macrophage 12-lipoxygenase activity. (A) Murine monocytic J774 cells were labeled with 50 μCi of [³H]arachidonic acid (AA) for 16 h. After thorough washing, the percentage of incorporated ³H released (mean ± SD) from labeled J774 cells into the conditioned medium (CM) in the absence (shaded bars) and presence (solid bars) of zymosan (4 mg/ml) was determined by liquid scintillation after 1 or 24 h (*p < 0.01 by Student’s t test). (B) Primary cultures of ALFs were untreated (lane 1) or were treated with 50% zymosan-stimulated J774-CM obtained in the absence (lane 2) or presence of 100 μM NDGA (lane 3), 10 μM NDGA (lane 4), 25 μM MK-886 (lane 5), 50 μM caffeic acid (lane 6), 50 μM CDC (lane 7), or 1 μg/ml indomethacin (lane 8). After 24 h, cells were harvested for Northern blot analysis of collagenase-3 (C’ase) and glyceraldehyde-3-phosphate dehydrogenase (GAP) mRNAs.