Figure 2.
Effects of constitutive SSTR3 activity on basal GH synthesis. A, Relative intracellular cAMP in untreated GpSSTR3WT and GpCon (n = 4). Samples were measured with the LANCE cAMP assay kit. B, Basal PKA activity assayed with a PepTag nonradioactive PKA assay. Phosphorylated peptide migrates toward the negative charge and nonphosphorylated peptide migrates toward the positive charge, representative of 3 repeated experiments. Ctrl, control. C, Baseline rGH promoter activity in untreated GpSSTR3WT and GpCon at 48 hours post-transfection (n = 6) (normalized to the internal Renilla luciferase control). D, Effect of 24 hours of 1 μM forskolin on rGH promoter activity expressed as fold change from nontreated cells (n = 3). E and F, Effect of 24-hour cAMP stimulation by 1 μM forskolin (n = 4) and 3 mM 8-Br-cAMP (n = 3) on rGH expression, respectively. *, P < .05; **, P < .01.