Fig. 2.

Effects of exogenous superoxide on U46619-induced contraction in IPA. A: LY83583 (LY, 1 µM, 15 min, n=12) generates superoxide in PASMC, as measured by L-012 chemi-luminescence), and this is inhibited by ebselen (ebs, 10 µM, n=10) or Tempol (temp, 3 mM, n=10). **P<0.001 vs. control, ##P<0.001 vs. LY alone. B-E: Effects of LY83583 and inhibitors on U46619-induced contraction in IPA. U46619 concentration was adjusted in each case to produce contractions equivalent to ~10% of KPSS (U46). 1 µM LY83583 was then added for 10 min (U46+LY). This response was then repeated in the presence of either DMSO vehicle (B, n=6), ebselen (C, 10 µM, n=7), Tempol (D, 3 mM, n=11) or PP2 (E, 30 µM, n=8). Left panels: representative traces. Right panels: mean ± SEM measurements of peak LY83583-induced contraction, expressed as a percentage of the U46619 pre-constriction. *P<0.05 vs. U46; **P<0.01 vs. U46, ##P<0.001 vs. control U46+LY (2-way ANOVA).