BACKGROUND Dopamine signaling is mediated by Gs protein-coupled "D1-like" receptors (D1 and D5) and Gi-coupled "D2-like" receptors (D2-4). In asthmatic patients, inhaled dopamine induces bronchodilation. Although the Gi-coupled dopamine D2 receptor is expressed and sensitizes adenylyl cyclase activity in airway smooth muscle (ASM) cells, the Gs-coupled dopamine D1-like receptor subtypes have ne...

Rats were treated for 21 d with the selective D1 dopamine receptor antagonist SCH23390, the selective D2 dopamine receptor antagonist spiperone, the nonselective dopamine receptor antagonist cis-flupentixol, or a combination of SCH23390 and spiperone. In addition, a group of rats received L-prolyl-L-leucyl-glycinamide (PLG) for 5 d after the 21 d chronic spiperone treatment. Chronic treatment w...

In the present study, the effects of intra-cerebral hippocampus (CA1) injections of apomorphine D1, D2-like receptors agonists on morphine-induced place preference in male Wistar rats have been investigated. Subcutaneous administration of different dose of morphine sulphate (1, 3, 6 and 9 mg/kg) produced a dose-dependent conditioned place preference (CPP). Intra-cerebral hippocampus (CA1) admin...

The role of dopamine receptors in the modulation of nucleus accumbens noradrenaline release was investigated in superfused rat brain slices. At concentrations of </=1 microM, dopamine enhanced, whereas at higher concentrations dopamine inhibited electrically evoked [3H]noradrenaline release. The D1 receptor agonist SKF-38393 increased, whereas the D2 agonist quinpirole inhibited evoked [3H]nora...

Background: Dopamine receptors comprise two subgroups, Gs protein-coupled “D1-like” receptors (D1, D5) and Gicoupled “D2-like” receptors (D2, D3, D4). In airways, both dopamine D1 and D2 receptors are expressed on airway smooth muscle and regulate airway smooth muscle force. However, functional expression of the dopamine D1 receptor has never been identified on airway epithelium. Activation of ...

The dopamine receptors have been classified into two groups, the D1like and D2-like dopamine receptors, respectively, based on molecular biology and pharmacological studies. The D1-like dopamine receptors comprise the D1 and D5 dopamine receptors and the D2-like dopamine receptors include the D2, D3 and D4 dopamine receptors. The gene structures of these two classes of receptors are dissimilar ...

In the periphery, physiological dopamine increases renal blood flow, decreases renal resistance and acts on the kidney tubule to enhance natriuresis and diuresis. Dopamine receptors can be divided into D1-like (D1 and D5) receptors that stimulate adenylyl cyclase and D2-like (D2, D3 and D4) receptors that inhibit adenylyl cyclase. Both the D1-like and D2-like receptors are expressed in the kidn...

In vivo administration or in vitro application of dopamine or of dopamine receptor agonists induce vasodilatation in the cerebral, coronary, renal and mesenteric vascular beds and cause hypotension. Moreover, dopamine stimulates cardiac contractility and induces diuresis and natriuresis. Peripheral (cardiovascular and renal) dopamine receptors belong to the D1-like and D2-like receptor superfam...

The tight correlation between the clinical potency and the D2R blocking action of antipsychotic medications suggests that dopamine hyperactivity plays a significant role in psychosis. Clozapine, one of the most effective antipsychotic drugs, has been shown to display moderate affinity for various neurotransmitter receptors, including the dopamine D1 and D2 receptors; however, the exact mechanis...

Dopamine is an important neurotransmitter regulating light-dark adaptation in the retina. The effect of dopamine is widespread and dependent on the localization of its receptors. We performed single cell RT-PCR on A-type horizontal cells visually selected from dissociated rabbit retinal neurons. Dopamine D1-receptor mRNA was positively identified. Subsequent sequencing of the fragment showed 82...