Figure 4.

Antithetic regulation of G_αq receptor signaling by βAR activity in isolated airway smooth muscle cells. Primary airway smooth muscle cell cultures were established from tracheas from the βAR^–/–, the β₂AR-OE, and their wild-type (WT) littermates. Maximal whole-cell inositol phosphate accumulation in response to carbachol (CCh), serotonin, and U46619 were reduced in βAR^–/– cells and increased in the β₂AR-OE cells (P < 0.01 for all responses versus wild-type littermates). Results are from five experiments performed in triplicate.