Figure 9. Inhibition Gβγ signaling prevents rolipram-sensitive changes in agonist responsiveness in IL-13-exposed rabbit ASM tissues.

Relative to controls, ASM tissues sensitized with IL-13 (50 ng/ml×24 hr) exhibit significantly increased contractility to ACh (A) and impaired relaxation to isoproterenol (B). Inhibition of Gβγ signaling by pretreatment with anti-Gβγ blocking peptide or gallein, or inhibition of PDE4 activity with rolipram, prevents IL-13-induced changes in ASM responsiveness. Data are mean ± SD values from 5–6 experiments. ANOVA used for multiple comparisons of mean Tmax and Rmax values. *p<0.05; **p<0.01.