Fig 1. Inhibition of Gβγ signaling suppresses intrinsically increased PDE activity in asthmatic HASM cells: Comparison of suppressive effects of anti-Gβγ blocking peptide vs. gallein.

Relative to normal cells, asthmatic HASM cells exhibit significantly increased constitutive (baseline) PDE activity. Inhibition of Gβγ signaling with a maximal effective concentration (1 μM) of either anti-Gβγ blocking peptide (A) or gallein (B) acutely suppresses PDE activity in asthmatic HASM cells to normal levels at 0.25 hr. Contrasting sustained inhibition of PDE activity in cells treated with anti-Gβγ blocking peptide, suppression of PDE activity in asthmatic HASM cells treated with gallein is transient, with progressive recovery in PDE activity after 1 hr that approaches near basal elevated levels by 24 hr. Data are mean ± SE values of 5–8 determinations made at each time point Comparisons are made using two-tailed Student t-test. *p<0.05; **p<0.01.