Figure 4.

F15063 antagonizes cloned human and native rat D₂ receptors. (a) F15063 induces a rightward shift of a concentration-effect curve of apomorphine-induced stimulation of [³⁵S]GTPγS binding to membranes of Sf9 cells expressing recombinant hD_2L receptors. Points are mean±s.e.m. of values from three experiments performed in triplicate. (b) Schild plot of the data from (a). (c) F15063 reverses the stimulation of ERK1/2 phosphorylation induced by dopamine in CHO cells expressing recombinant hD_2S receptors. (d) F15063 antagonizes quinelorane-induced [³⁵S]GTPγS binding to rat striatal membranes. Points are mean±s.e.m. of values from three experiments performed in triplicate. For comparative purposes, the dotted line represents the results obtained for haloperidol under the same conditions. Data from these experiments are shown in Table 6.