Table 1.
Stable Cell Lines | Kd (nM) | Bmax (fmol/mg) | DAMGO EC50 (μM) | Maximal Inhibition of cAMP Accumulation (%) |
---|---|---|---|---|
MOP | 2.6 ± 0.8 | 54 ± 5.4 | 3.4 ± 1.7 | 78 ± 7.8 |
MOP+RanBPM | 2.8 ± 0.7 | 49 ± 6.2 | 2.1 ± 0.8 | 79 ± 4.3 |
The binding characteristics (Kd and Bmax) for [3H]naloxone were determined on membranes from HEK293 cells stably transfected with FLAG-MOP ± RanBPM and analyzed by computerized curve fitting (see Materials and Methods). DAMGO-mediated inhibition of cAMP accumulation was assessed as described in the same cells by [3H]adenine labeling and determining percent conversion of [3H]ATP to [3H]cAMP in the presence of 10 μM forskolin and 200 μM IBMX. Data shown are mean ± S.E.M. of three independent experiments each performed in duplicate.