Figure 4
LTD 4 -induced ERK1/2 phosphorylation. (A) Increase of [3H]thymidine incorporation induced by 1 μM LTD4 and 20 ng/ml EGF alone and in combination in the absence and presence of 20 μM PD98059 (1 h preincubation). Control is represented by MEM additioned with 1% FBS. The results are presented as mean ± S.E.M. of three experiments performed in triplicate on two different cell lines. **P < 0.01 (one-way ANOVA). (B) ERK1/2 phosphorylation induced by 10 nM LTD4 (n = 12) and 0.01 ng/ml EGF (5 minutes) alone and in combination (n = 4). The results are presented as mean ± S.E.M. (C) ERK1/2 phosphorylation induced by 10 nM LTD4 and 0.01 ng/ml EGF (5 minutes) alone and in combination in the absence and presence of 20 μM PD98059 (1 h preincubation). (D) Effect of 1 μM zafirlukast and pranlukast (30 minutes pretreatment) on ERK1/2 phosphorylation induced by 10 nM LTD4 (5 min). 0.1 ng/ml EGF was used as an internal control. (E) ERK1/2 phosphorylation induced by 10 nM LTD4, 0.1 ng/ml EGF (5 minutes), alone or in combination, in the absence and presence of 250 nM AG1478 (1 h preincubation). (D-E) The results presented are representative of at least three experiments performed on two different cell lines.