Fig. 6

Dexamethasone reduces monocrotaline (MCT)-induced enhancement of phospho-IKK-α/β immunostaining in rat lung vascular cells. The expression of activated phospho-IKKα/β (brown staining) was measured in lung sections from rats from untreated control rats (a); day 28 MCT-treated rats (b) and MCT and dexamethasone day 14–28-treated rats (c). These data suggest an increase in IKKα/β activation in the EC layer in MCT rats (black arrow) (b), which was reduced in dexamethasone-treated rats (unfilled arrow) (c). Sections represent n = 2–3 per group (a–c); and were counterstained with haematoxylin. Antibody-negative control is shown in slide D. Magnification x100 (b, c) and ×200 (a, d). Phospho (P)-Stat3 and Stat3 staining was performed in control, MCT and MCT + Dex rats (n = 3 per group), with SMA staining of smooth muscle actin (bottom panel, magnification x200) (e). The results show that MCT enhances P-stat3 expression and that this is reduced in the presence of dexamethasone