FIGURE 3.

Dose-dependent NO release for (a–d) compounds 5, 10, 11 and 25 in Be2C cells transfected with 7TM-μ receptors (7TM-MOR), 6TM-μ receptors (6TM-MOR), β₂-adrenoceptors (β₂-AR) or 6TM-MOR+β₂-AR. (a) Compound 5 (n = 4, 4, 3 and 4 per dose tested in 7TM-MOR, 6TM-MOR, β₂-AR and 6TM-MOR/β₂-AR transfected cell line, respectively) induced a dose-dependent release of NO in 7TM-MOR transfected cells only. Compounds (b) 10 (n = 3, 4, 3 and 4 per dose tested in 7TM-MOR, 6TM-MOR, β₂-AR and 6TM-MOR/β₂-AR transfected cell line, respectively), (c) 11 (n = 3, 4, 3 and 4 per dose tested in 7TM-MOR, 6TM-MOR, β₂-AR and 6TM-MOR/β₂-AR transfected cell line, respectively) and (d) 25 (n = 3 for log doses −8.0, −7.0 and −6.0 per transfected cell line and n = 3, 5, 3 and 5 in 7TM-MOR, 6TM-MOR, β₂-AR and 6TM-MOR/β₂-AR transfected cell lines, respectively, for log doses −5.0, −4.3 and −4.0) induced a dose-dependent release of NO in 6TM-MOR transfected cells, and this effect was potentiated by co-transfection with β₂-AR. None of the compounds released NO when the cells were transfected only with β₂-AR. Data expressed as mean ± SEM