Dopamine receptors are a class of G protein-coupled receptors that are prominent in the vertebrate central nervous system (CNS). Dopamine receptors activate different effectors through not only G-protein coupling, but also signaling through different protein interactions. The neurotransmitter dopamine is the primary endogenous ligand for dopamine receptors.
The adenosine receptors (or P1 receptors) are a class of purinergic G protein-coupled receptors with adenosine as the endogenous ligand. There are four known types of adenosine receptors in humans: A1, A2A, A2B and A3; each is encoded by a different gene.
Lisuride, sold under the brand name Dopergin among others, is a monoaminergic medication of the ergoline class which is used in the treatment of Parkinson's disease, migraine, and high prolactin levels. It is taken by mouth.
A heteromer is something that consists of different parts; the antonym of homomeric. Examples are:
Dopamine receptor D2, also known as D2R, is a protein that, in humans, is encoded by the DRD2 gene. After work from Paul Greengard's lab had suggested that dopamine receptors were the site of action of antipsychotic drugs, several groups, including those of Solomon H. Snyder and Philip Seeman used a radiolabeled antipsychotic drug to identify what is now known as the dopamine D2 receptor. The dopamine D2 receptor is the main receptor for most antipsychotic drugs. The structure of DRD2 in complex with the atypical antipsychotic risperidone has been determined.
The adenosine A2A receptor, also known as ADORA2A, is an adenosine receptor, and also denotes the human gene encoding it.
Dopamine receptor D1, also known as DRD1. It is one of the two types of D1-like receptor family — receptors D1 and D5. It is a protein that in humans is encoded by the DRD1 gene.
SCH-58261 is a drug which acts as a potent and selective antagonist for the adenosine receptor A2A, with more than 50x selectivity for A2A over other adenosine receptors. It has been used to investigate the mechanism of action of caffeine, which is a mixed A1 / A2A antagonist, and has shown that the A2A receptor is primarily responsible for the stimulant and ergogenic effects of caffeine, but blockade of both A1 and A2A receptors is required to accurately replicate caffeine's effects in animals. SCH-58261 has also shown antidepressant, nootropic and neuroprotective effects in a variety of animal models, and has been investigated as a possible treatment for Parkinson's disease.
Istradefylline, sold under the brand name Nourianz, is a medication used as an add-on treatment to levodopa/carbidopa in adults with Parkinson's disease (PD) experiencing "off" episodes. Istradefylline reduces "off" periods resulting from long-term treatment with the antiparkinson drug levodopa. An "off" episode is a time when a patient's medications are not working well, causing an increase in PD symptoms, such as tremor and difficulty walking.
ZM-241,385 is a high affinity antagonist ligand selective for the adenosine A2A receptor.
SCH-442,416 is a highly selective adenosine A2a subtype receptor antagonist. It is widely used in its 11C radiolabelled form to map the distribution of A2a receptors in the brain, where they are mainly found in the striatum, nucleus accumbens, and olfactory tubercle. Given its distribution in the brain, A2a receptors have been investigated for the treatment of various neurological disorders, and SCH-442,416 has shown promise in treatment of depression, Parkinson's disease, and catalepsy.
Preladenant is a drug that was developed by Schering-Plough which acted as a potent and selective antagonist of the adenosine A2A receptor. It was being researched as a potential treatment for Parkinson's disease. Positive results were reported in Phase II clinical trials in humans, but it did not prove itself to be more effective than a placebo during Phase III trials, and so was discontinued in May 2013.
Sonepiprazole (U-101,387, PNU-101,387-G) is a drug of the phenylpiperazine class which acts as a highly selective D4 receptor antagonist. In animals, unlike D2 receptor antagonists like haloperidol, sonepiprazole does not block the behavioral effects of amphetamine or apomorphine, does not alter spontaneous locomotor activity on its own, and lacks extrapyramidal and neuroendocrine effects. However, it does reverse the prepulse inhibition deficits induced by apomorphine, and has also been shown to enhance cortical activity and inhibit stress-induced cognitive impairment. As a result, it was investigated as an antipsychotic for the treatment of schizophrenia in a placebo-controlled clinical trial, but in contrast to its comparator olanzapine no benefits were found and it was not researched further for this indication.
PNU-99,194(A) (or U-99,194(A)) is a drug which acts as a moderately selective D3 receptor antagonist with ~15-30-fold preference for D3 over the D2 subtype. Though it has substantially greater preference for D3 over D2, the latter receptor does still play some role in its effects, as evidenced by the fact that PNU-99,194 weakly stimulates both prolactin secretion and striatal dopamine synthesis, actions it does not share with the more selective (100-fold) D3 receptor antagonists S-14,297 and GR-103,691.
L-741,626 is a drug which acts as a potent and selective antagonist for the dopamine receptor D2. It has good selectivity over the related D3 and D4 subtypes and other receptors. L-741,626 is used for laboratory research into brain function and has proved particularly useful for distinguishing D2 mediated responses from those produced by the closely related D3 subtype, and for studying the roles of these subtypes in the action of cocaine and amphetamines in the brain.
F-15,063 is an orally active potential antipsychotic, and an antagonist at the D2/D3 receptors, partial agonist at the D4 receptor, and agonist at the 5-HT1A receptors. It has greater efficacy at the 5-HT1A receptors than other antipsychotics, such as clozapine, aripiprazole, and ziprasidone. This greater efficacy may lead to enhanced antipsychotic properties, as antipsychotics that lack 5-HT1A affinity are associated with increased risk of extrapyramidal symptoms, and lack of activity against the negative symptoms of schizophrenia.
Theacrine, also known as 1,3,7,9-tetramethyluric acid, is a purine alkaloid found in Cupuaçu and in a Chinese tea known as kucha. It shows anti-inflammatory and analgesic effects and appears to affect adenosine signalling in a manner similar to caffeine. In kucha leaves, theacrine is synthesized from caffeine in what is thought to be a three-step pathway. Theacrine and caffeine are structurally similar.
Adenosine A2A receptor antagonists are a class of drugs that blocks adenosine at the adenosine A2A receptor. Notable adenosine A2A receptor antagonists include caffeine, theophylline and istradefylline.
A pro-motivational agent is a drug which increases motivation. They can be used in the treatment of motivational deficits, for instance in depression, schizophrenia, and attention deficit hyperactivity disorder (ADHD), as well as in the treatment of disorders of diminished motivation (DDMs), including apathy, abulia, and akinetic mutism, for instance due to stroke, traumatic brain injury, or neurodegenerative diseases. They are also used non-medically by healthy people to increase motivation and productivity, for instance in educational contexts.
MSX-3 is a selective adenosine A2A receptor antagonist used in scientific research. Similarly to MSX-4, it is a water-soluble ester prodrug of MSX-2.
