Figure 1.

Effects of GF109203X, PD98059, wortmannin and dibutyryl cAMP or forskolin on neutrophil-mediated proteoglycan degradation. Neutrophils (4 × 10⁶) were preincubated in the absence or presence of 0·5 µm GF109203X (a), 50 µm PD98059 (b), 150 nm wortmannin (c) and 0·5 mm dibutyryl cAMP or 1 µm forskolin in the presence of 1 mm isobutylmethylxanthine (d) for 15, 45, 30 and 30 min, respectively, before being incubated with ³⁵S-sulphur prelabelled bovine articular cartilage. Proteoglycan degradation was assessed as described in the Materials and Methods. Results, as means ±SEM of at least three experiments conducted in triplicates and using cells from different donors, are expressed as percentage of ³⁵S-labelled proteoglycan released during a 2·5-h incubation period. Significance of difference between the presence and absence of an inhibitor/agent: **P < 0·001.