The D2-like receptors [1] are a subfamily of dopamine receptors that bind the endogenous neurotransmitter dopamine. The D2-like subfamily consists of three G-protein coupled receptors that are coupled to Gi/Go and mediate inhibitory neurotransmission, of which include D2, D3, and D4. For more information, please see the respective main articles of the individual subtypes:
Pergolide, sold under the brand name Permax and Prascend (veterinary) among others, is an ergoline-based dopamine receptor agonist used in some countries for the treatment of Parkinson's disease. Parkinson's disease is associated with reduced dopamine synthesis in the substantia nigra of the brain. Pergolide acts on many of the same receptors as dopamine to increase receptor activity.
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.
A dopamine antagonist, also known as an anti-dopaminergic and a dopamine receptor antagonist (DRA), is a type of drug which blocks dopamine receptors by receptor antagonism. Most antipsychotics are dopamine antagonists, and as such they have found use in treating schizophrenia, bipolar disorder, and stimulant psychosis. Several other dopamine antagonists are antiemetics used in the treatment of nausea and vomiting.
An autoreceptor is a type of receptor located in the membranes of nerve cells. It serves as part of a negative feedback loop in signal transduction. It is only sensitive to the neurotransmitters or hormones released by the neuron on which the autoreceptor sits. Similarly, a heteroreceptor is sensitive to neurotransmitters and hormones that are not released by the cell on which it sits. A given receptor can act as either an autoreceptor or a heteroreceptor, depending upon the type of transmitter released by the cell on which it is embedded.
SKF-82,958 is a synthetic compound of the benzazepine class that acts as a D1/D5 receptor full agonist. SKF-82,958 and similar D1-like-selective full agonists like SKF-81,297 and 6-Br-APB produce characteristic anorectic effects, hyperactivity and self-administration in animals, with a similar but not identical profile to that of dopaminergic stimulants such as amphetamine. SKF-82,958 was also subsequently found to act as an agonist of ERα with negligible activity at ERβ, making it a subtype-selective estrogen.
Pramipexole, sold under the brand Mirapex among others, is a medication used to treat Parkinson's disease (PD) and restless legs syndrome (RLS). In Parkinson's disease it may be used alone or together with levodopa. It is taken by mouth. Pramipexole is a dopamine agonist of the non-ergoline class.
A dopamine agonist is a compound that activates dopamine receptors. There are two families of dopamine receptors, D1-like and D2-like. They are all G protein-coupled receptors. D1- and D5-receptors belong to the D1-like family and the D2-like family includes D2, D3 and D4 receptors. Dopamine agonists are primarily used in the treatment of the motor symptoms of Parkinson's disease, and to a lesser extent, in hyperprolactinemia and restless legs syndrome. They are also used off-label in the treatment of clinical depression. Impulse control disorders are associated with the use of dopamine agonists for whatever condition.
Piribedil (trade names Pronoran, Trivastal Retard, Trastal, Trivastan, Clarium and others) is an antiparkinsonian agent and piperazine derivative which acts as a D2 and D3 receptor agonist. It also has α2-adrenergic antagonist properties.
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.
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.
Dopamine receptor D3 is a protein that in humans is encoded by the DRD3 gene.
UH-232 ((+)-UH232) is a drug which acts as a subtype selective mixed agonist-antagonist for dopamine receptors, acting as a weak partial agonist at the D3 subtype, and an antagonist at D2Sh autoreceptors on dopaminergic nerve terminals. It causes dopamine release in the brain and has a stimulant effect, as well as blocking the behavioural effects of cocaine. It may also serve as a 5-HT2A receptor agonist, based on animal studies. It was investigated in clinical trials for the treatment of schizophrenia, but unexpectedly caused symptoms to become worse.
The D1-like receptors are a subfamily of dopamine receptors that bind the endogenous neurotransmitter dopamine. The D1-like subfamily consists of two G protein–coupled receptors that are coupled to Gs and mediate excitatory neurotransmission, of which include D1 and D5. For more information, please see the respective main articles of the individual subtypes:
AS-8112 is a synthetic compound that acts as a selective antagonist at the dopamine receptor subtypes D2 and D3, and the serotonin receptor 5-HT3. It has potent antiemetic effects in animal studies and has been investigated for potential medical use.
7-OH-DPAT is a synthetic compound that acts as a dopamine receptor agonist with reasonable selectivity for the D3 receptor subtype, and low affinity for serotonin receptors, unlike its structural isomer 8-OH-DPAT. 7-OH-DPAT is self-administered in several animal models, and is used to study its addiction effects to cocaine.
SKF-81,297 is a synthetic drug of the benzazepine chemical class that acts as a selective dopamine D1/D5 receptor full agonist, and produces a characteristic stimulant-like pattern of anorexia, hyperactivity and self-administration in animals. This profile is shared with several related drugs such as 6-Br-APB and SKF-82,958, but not with certain other D1 full agonists such as A-77,636, reflecting functional selectivity of D1 activation. Newer findings reveal that SKF-81,297 additionally acts as a partial agonist at D1-D2 receptor heteromers.
CY-208,243 is a drug which acts as a dopamine agonist selective for the D1 subtype. Unlike most D1-selective agonists, it shows efficacy in animal models of Parkinson's disease.
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.
The prostaglandin D2 (PGD2) receptors are G protein-coupled receptors that bind and are activated by prostaglandin D2. Also known as PTGDR or DP receptors, they are important for various functions of the nervous system and inflammation. They include the following proteins: