FIGURE 5.

Stimulation of a G-protein regulated AC by CO₂in vivo. a, monitoring of HEK 293T cell pH_i in response to changing CO₂. b, percentage conversion of ATP into cAMP in HEK 293T cells exposed to varying CO₂ under basal conditions (empty bars) or in the presence of 50 nm isoproterenol (filled bars)(n = 12). c, percentage conversion of ATP into cAMP in HEK 293T cells exposed to air (0.03% CO₂; open bars) or 5% (v/v) CO₂ (filled bars) with 5 μm forskolin and 1 μm KH7 (n = 12; *, p < 0.05). d, lower panel shows immunoblot of HEK 293T cell material after treatment with and without isoproterenol at varying CO₂. The upper panel shows the ratio of phospho-CREB:α-tubulin bands from the quantified bands.