Figure 8.

Pharmacological specificity of ligand-induced upregulation of CAM adrenoceptors. A clone of HEK293 cells stably expressing a CAM α_1b-adrenoceptor-GFP construct (Stevens et al., 2000) was transiently transfected for 24 h to express CAM β₂-adrenoceptor-Renilla luciferase. The cells were then exposed to either betaxolol (10 μM) (1) or to the α₁-adrenoceptor antagonist/inverse agonist phentolamine (10 μM) (2) for 24 h. Renilla luciferase activity (as bioluminescence) and GFP fluorescence were then monitored in parallel. Results are presented as per cent of the signals obtained by treatment of the cells with vehicle and represent means±s.e.mean from three independent experiments.