In search of a cell line in which the D3 dopamine receptor is expressed endogenously, we found that the neuron-derived human medulloblastoma cell line TE671 expresses the human D3 (hD3) and D1 (hD1) receptor, but neither the D2 or D4 receptors. Exposure of TE671 cells to the D3 agonist 7-OH-DPAT (DPAT), or to the D1 agonist SKF-38393 (SKF) increased the expression of hD3 or hD1 mRNA, respective...

The novel selective D1 dopaminergic full agonists A-68930, A-77636 were discovered by the synthesis of molecules to probe the bioactive conformation of the partial agonist SKF-38393, by the use of this information to add D1 affinity and selectivity to a screening hit, and by traditional medicinal chemistry exploration of structure-activity relationships. The subsequent design of A-86929 and ABT...

Dopaminergic denervation supersensitivity has been implicated in the pathogenesis of levodopa-induced dyskinesias, the most common and limiting side effect in the drug treatment of Parkinson's disease, yet the mechanisms that mediate altered drug sensitivity remain poorly understood. In animals models, one key component of denervation supersensitivity is the enhanced efficacy of selective D1 ag...

*Address correspondence to: Sonia Trías. Department of Cell Biology, University of Málaga, 29071 Málaga, Spain. e-mail: [email protected] ABSTRACT D1-like (D1 and D5) and D2-like (D2, D3 and D4) dopamine receptor subtypes interact synergistically in many paradigms, such as dopamine (DA) agonist-stimulated motor behaviour and striatal c-Fos expression in intact and DA-depleted striatum. However, it ...

Using pharmacological approaches, we obtained evidence for the release of dopamine (DA) and its dopaminergic regulation in the guinea pig spinal cord. Electrical stimulation of the cord pieces increased the endogenous DA release and the efflux of [3H]dopamine [( 3H]DA) from tissues preloaded with [3H]DA. The evoked release of [3H]DA was current- and frequency-dependent and was prevented by tetr...

To explore associations of neostriatal (NST) endogenous levels of dopamine (DA) and serotonin (5-HT) with sensitivity of their receptors, graded doses of 6-hydroxydopamine HBr (0 to 400 micrograms, ICV; 6-OHDA; desipramine pretreatment, 20 mg/kg IP) were given to rats between birth (P 0) and P 42. Numbers of vacuous chewing movements (VCMs) induced by SKF 38393 or m-chlorophenylpiperazine (m-CP...

The effects of dopamine receptor agonists on the levels of the striatal serotonin 5-HT2A receptor and its mRNA were investigated in rats lesioned with 6-OHDA as neonates. The mRNA encoding for the 5-HT2A receptor was detected by in situ hybridization histochemistry and the binding of 5-HT2A receptors was revealed with [125I](2,5-dimethoxy-4-iodophenyl)2-aminopropane ([125I]DOI). In adult contro...

Dopaminergic neurons of the substantia nigra provide one of the major neuromodulatory inputs to the neostriatum. Recent in situ hybridization experiments have suggested that postsynaptic dopamine receptors are segregated in striatonigral and striatopallidal neurons. We have tested this hypothesis in acutely isolated, retrogradely labeled striatonigral neurons by examining the neuromodulatory ef...

Dopamine interacts with distinct receptors on different target neurons in the rat retina. Dopamine receptors were labeled in the rat retina by autoradiography using 3H-SCH-23390 and 3H-spiperone binding to retinal sections. The 3H-SCH-23390 binding to D1 receptors was most concentrated in the inner plexiform, inner nuclear, and ganglion cell layers; it was absent from the outer nuclear layer an...

This study examined the effects of D2-like dopamine receptor activation on Na+-K+-ATPase activity while apical-to-basal, ouabain-sensitive, amphotericin B-induced increases in short-circuit current and basolateral K+ (I(K)) currents in opossum kidney cells were measured. The inhibitory effect of dopamin on Na+-K+-ATPase activity was completely abolished by either D1- or D2-like receptor antagon...