Table 2

Effect of opioid agonists on [35S]GTPγS binding:in vitro autoradiographic analysis in rat thalamus

AgonistStimulationMaximal/Stimulation
nCi/g % %
Basal319  ± 20N.A.N.A.
DAMGO627  ± 4896  ± 7.2100  ± 7.5
Fentanyl461  ± 5.036  ± 2.937  ± 1.5
Morphine430  ± 1835  ± 3.337  ± 5.0
Buprenorphine383  ± 6.413  ± 0.613  ± 2.3

Sections were incubated with opioid agonists (concentrations shown in legend to Fig. 2) in the presence of 0.04 nm[35S]GTPγS and 2 mm GDP. Data are mean ± standard error of absolute [35S]GTPγS binding, percent stimulation of [35S]GTPγS binding over basal, and percent of maximal stimulation produced by 5 μmDAMGO.

    • N.A., not applicable.