Figure 1. Effects of fasudil and hydroxyfasudil on the prostaglandin F_2α (PGF_2α)- or 12-deoxyphorbol 13-isobutyrate (DPB)-induced contraction and 20 kDa myosin light chain (MLC₂₀) phosphorylation in rabbit aortae.

Fasudil (▪) or hydroxyfasudil (OH-fasudil, (Δ) at 10 µm was added 20 min after the application of 10 µm PGF_2α (A) or 1 µm DPB (B). Left panels, a change in tension after the addition of fasudil or hydroxyfasudil (○, agonist alone). Tension is expressed as a percentage of contraction just before the addition of fasudil or hydroxyfasudil. In the right panels, MLC₂₀ phosphorylation (MLC-P) was observed 20 min after the addition of PGF_2α or DPB (just before the addition of fasudil or hydroxyfasudil (a) or 50 min after the addition of PGF_2α or DPB (b), and is expressed as a percentage of phosphorylated MLC₂₀ of total MLC₂₀. MLC₂₀ phosphorylation in the resting state was 8–9 % in each case (data not shown). Since PGF_2α caused diphosphorylation of MLC₂₀, monophosphorylation (MLC-P1, open columns) and diphosphorylation (MLC-P2, black columns) are shown (A, right panel). Data are presented as the mean ± s.e.m. (n = 5–6). * Significantly different from the time-matched control (P < 0.05).