Figure 3.
Effect of altering localized PKA activity of ISO-induced near-membrane cAMP signals in HASM cells. Localized cAMP signals were measured using C460W/E583M CNG channels as described in the text. A) ISO (1 μM) triggered transient activation of CNG channels, indicating a transient increase in near-membrane cAMP signals. Width at half height of this experiment is 167 s. B) Inclusion of 10 μM st-Ht31 in the patch pipette slowed the decay of transient cAMP signals. Width at half height of this experiment is 292 s. C) Inclusion of 20 nM PKI effectively prevented decays in cAMP signals. D) Response of a cell transfected with adenovirus encoding GFP to ISO. Little or no current was observed. Trace is representative of 7 experiments.