Apomorphine receptor binding

The biplots show which binding tests are predictive for which pharmacological tests. Binding to the haloperidol and apomorphine labeled receptors corresponds with inhibition of agitation and stereotypy in rats, binding to the spiperone receptor... 

Dopamine receptors may occur on the terminals of the glutamatergic afferents to the neostriatum (63). Following cortical ablation, the number of 3H]-haloperidol binding sites in the striatum is reduced by 32% (63). In an in vitro superfusion system, dopamine, apomorphine, amino tetralin derivatives or bromocriptine inhibit the depolarization-induced release of... 

Cannon, in 1975, suggested that dopamine might bind to Its receptors in two possible conformational extremes, which he designated the "alpha" and "beta" rotamers, XIa and Xlb, respectively (20). In this view apomorphine would represent a structure containing a dopamine fragment "frozen" into the alpha rotameric form. By contrast, 6,7-ADTN contains a dopamine moiety constrained in the beta rotameric form. In both cases the side chain is nearly coplanar with the aromatic ring and is... 

Fig. 4 A molecular model of the dopamine D2 receptor with a ligand docked in the binding site. The model of the D2 receptor transmembrane helices was constructed from the coordinates of the bacteriorhodopsin structure derived from two-dimensional electron diffraction experiments and is consistent with the projection structure for rhodopsin. The transmembrane helices are represented by a solid ribbon and the drug, apomorphine, is a space filling representation. The top view looking down the helical axis of the receptor clearly delineates the seven transmembrane helices that are the key structural motif for the GPCR superfamily. Some of the helices are inclined relative to the perpendicular to the membrane plane. The bottom view is in the plane of the membrane with the extracellular space at the top of the figure. (Adapted from Ref.t f)...

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