TABLE 3

Agonist and antagonist efficacies and potencies of selected agonist and antagonists in [35S]GTPγS binding assay using membranes from rat striatum, HEK293 cells expressing human D2, and CHO cells expressing human D3 receptors

Rat StriatumHEK-D2 CellsCHO-D3 Cells
AgonismAntagonismAgonismAntagonismAgonismAntagonism
EmaxpEC50AAmaxpKbEmaxpEC50AAmaxpKbEmaxpEC50AAmaxpKb
Dopamine154 ± 165.49 ± 0.17N.T.117 ± 96.01 ± 0.07N.T.N.T.101 ± 17.64 ± 0.09N.T.N.T.
Pramipexole56 ± 56.05 ± 0.13N.T.N.T.119 ± 136.60 ± 0.17N.T.N.T.121 ± 178.32 ± 0.09N.T.N.T.
Apomorphine177 ± 56.13 ± 0.07N.T.N.T.107 ± 138.10 ± 0.10N.T.N.T.125 ± 88.05 ± 0.07N.T.N.T.
7-OH-DPAT48 ± 146.87 ± 0.16N.T.N.T.79 ± 77.16 ± 0.09N.T.N.T.66 ± 28.73 ± 0.12N.T.N.T.
Quinpirole62 ± 96.09 ± 0.14N.T.N.T.96 ± 146.19 ± 0.08N.T.N.T.118 ± 68.02 ± 0.13N.T.N.T.
PHNO138 ± 96.96 ± 0.08N.T.N.T.122 ± 127.94 ± 0.34N.T.N.T.75 ± 128.91 ± 0.05N.T.N.T.
CariprazineN.S.N.S.107 ± 38.95 ± 0.17N.S.N.S.100 ± 19.12 ± 0.15N.S.N.S.99 ± 29.50 ± 0.07
AripiprazoleN.S.N.S.105 ± 38.79 ± 0.27N.S.N.S.101 ± 29.33 ± 0.10N.S.N.S.113 ± 48.71 ± 0.05
HaloperidolN.T.N.T.88 ± 18.44 ± 0.11N.T.N.T.105 ± 38.81 ± 0.07N.T.N.T.124 ± 28.51 ± 0.08
L741626N.T.N.T.83 ± 18.16 ± 0.11N.T.N.T.119 ± 38.13 ± 0.08N.T.N.T.122 ± 117.39 ± 0.14
SB-277011N.T.N.T.116 ± 76.13 ± 0.14N.T.N.T.54 ± 146.07 ± 0.04N.T.N.T.82 ± 58.07 ± 0.21
OlanzapineN.T.N.T.121 ± 87.72 ± 0.15N.T.N.T.105 ± 57.78 ± 0.16N.T.N.T.130 ± 287.30 ± 0.06
RisperidoneN.T.N.T.121 ± 28.22 ± 0.15N.T.N.T.112 ± 28.05 ± 0.08N.T.N.T.136 ± 237.57 ± 0.02
  • Given are the means ± S.E.M. from three to six independent experiments in duplicates or triplicates. Emax, maximal stimulation relative to 10 μM dopamine; AAmax, percentage maximal antagonism achieved. N.S., no stimulation; N.T., not tested.