scholarly journals N–Skatyltryptamines—Dual 5–HT6R/D2R Ligands with Antipsychotic and Procognitive Potential

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4605
Author(s):  
Agata Hogendorf ◽  
Adam Hogendorf ◽  
Rafał Kurczab ◽  
Grzegorz Satała ◽  
Bernadeta Szewczyk ◽  
...  
Keyword(s):  
Homology Modeling ◽  
Dopamine Receptors ◽  
Memory Impairment ◽  
D2 Receptor ◽  
Antipsychotic Agents ◽  
D2 Receptors ◽  
Rodent Models ◽  
Murine Models ◽  
Cyp Inhibition ◽  
The Difference

A series of N-skatyltryptamines was synthesized and their affinities for serotonin and dopamine receptors were determined. Compounds exhibited activity toward 5-HT1A, 5-HT2A, 5-HT6, and D2 receptors. Substitution patterns resulting in affinity/activity switches were identified and studied using homology modeling. Chosen hits were screened to determine their metabolism, permeability, hepatotoxicity, and CYP inhibition. Several D2 receptor antagonists with additional 5-HT6R antagonist and agonist properties were identified. The former combination resembled known antipsychotic agents, while the latter was particularly interesting due to the fact that it has not been studied before. Selective 5-HT6R antagonists have been shown previously to produce procognitive and promnesic effects in several rodent models. Administration of 5-HT6R agonists was more ambiguous—in naive animals, it did not alter memory or produce slight amnesic effects, while in rodent models of memory impairment, they ameliorated the condition just like antagonists. Using the identified hit compounds 15 and 18, we tried to sort out the difference between ligands exhibiting the D2R antagonist function combined with 5-HT6R agonism, and mixed D2/5-HT6R antagonists in murine models of psychosis.

scholarly journals Dopamine agonists and antipsychotics

2020 ◽  
Vol 183 (3) ◽  
pp. C11-C13
Author(s):  
Mark E Molitch
Keyword(s):  
Dopamine Receptors ◽  
Dopamine Agonists ◽  
Dopamine D2 Receptor ◽  
Rare Complication ◽  
D2 Receptor ◽  
Size Control ◽  
Antipsychotic Agents ◽  
Blocking Effect ◽  
Psychiatric Disease ◽  
Psychiatric Status

There can potentially be a number of clinical interactions that could adversely affect patient outcomes in a patient with a prolactinoma and psychiatric disease that might require antipsychotic and dopamine agonist treatment. Dopamine agonists stimulate the dopamine D2 receptor, resulting in a decrease in prolactin (PRL) levels and in prolactinoma size but action on dopamine receptors in the meso-limbic system may rarely cause psychosis and more commonly cause impulse control disorders. The psychiatric benefits of antipsychotic agents involve blocking the D2 and other dopamine receptors but this blockade often also causes hyperprolactinemia. In patients with macroprolactinomas and psychosis, observation, estrogen/progestin replacement, and surgery can be considered in addition to dopamine agonists. In those who require dopamine agonists for PRL and tumor size control, the introduction of antipsychotics may blunt this effect, so that higher doses of the dopamine agonists may be needed. Alternatively, antipsychotics that have less of a blocking effect at the D2 receptor, such as aripiprazole, can be tried, if appropriate. For patients already on antipsychotic drugs who are found to have a macroprolactinoma for which dopamine agonists are required, dopamine agonists can be initiated at low dose and the dose escalated slowly. However, such patients require careful monitoring of psychiatric status to avoid the rare complication of exacerbation of the underlying psychosis. Again, if appropriate, use of antipsychotics that have less of a blocking effect at the D2 receptor may allow lower doses of dopamine agonists to be used in this situation.

scholarly journals The renal dopamine receptors.

1992 ◽  
Vol 2 (8) ◽  
pp. 1265-1278
Author(s):  
P A Jose ◽  
J R Raymond ◽  
M D Bates ◽  
A Aperia ◽  
R A Felder ◽  
...  
Keyword(s):  
Amino Acids ◽  
Adenylyl Cyclase ◽  
Dopamine Receptors ◽  
Dopamine Receptor ◽  
D2 Receptor ◽  
D2 Receptors ◽  
Receptor Subtypes ◽  
Renal Dopamine ◽  
The Brain ◽  
Stimulation Of

Dopamine is an endogenous catecholamine that modulates many functions including behavior, movement, nerve conduction, hormone synthesis and release, blood pressure, and ion fluxes. Dopamine receptors in the brain have been classically divided into D1 and D2 subtypes, based on pharmacological data. However, molecular biology techniques have identified many more dopamine receptor subtypes. Several of the receptors cloned from the brain correspond to the classically described D1 and D2 receptors. Several D1 receptor subtypes have been cloned (D1A, D1B, and D5) and are each coupled to the stimulation of adenylyl cyclase. The D2 receptor has two isoforms, a shorter form, composed of 415 amino acids, is termed the D2short receptor. The long form, called the D2long receptor, is composed of 444 amino acids; both are coupled to the inhibition of adenylyl cyclase. The D3 and D4 receptors are closely related to, but clearly distinct from, the D2 receptor. They have not yet been linked to adenylyl cyclase activity. Outside of the central nervous system, the peripheral dopamine receptors have been classified into the DA1 and DA2 subtypes, on the basis of synaptic localization. The pharmacological properties of DA1 receptors roughly approximate those of D1 and D5 receptors, whereas those of DA2 receptors approximate those of D2 receptors. A renal dopamine receptor with some pharmacological features of the D2 receptor but not linked to adenylyl cyclase has been described in the renal cortex and inner medulla. In the inner medulla, this D2-like receptor, termed DA2k, is linked to stimulation of prostaglandin E2 production, apparently due to stimulation of phospholipase A2. Of the cloned dopamine receptors, only the mRNA of the D3 receptor has been reported in the kidney. The DA1 receptor in the kidney is associated with renal vasodilation and an increase in electrolyte excretion. The DA1-related vasodilation and inhibition of electrolyte transport is mediated by cAMP. The role of renal DA2 receptors remains to be clarified. Although DA1 and DA2 receptors may act in concert to decrease transport in the renal proximal convoluted tubule, the overall function of DA2 receptors may be actually the opposite of those noted for DA1 receptors. Dopamine has been postulated to act as an intrarenal natriuretic hormone. Moreover, an aberrant renal dopaminergic system may play a role in the pathogenesis of some forms of hypertension. A decreased renal production of dopamine and/or a defective transduction of the dopamine signal is/are present in some animal models of experimental hypertension as well as in some forms of human essential hypertension.

Extraversion and Dopamine

1998 ◽  
Vol 3 (1) ◽  
pp. 37-50 ◽  
Author(s):  
Thomas H. Rammsayer
Keyword(s):  
Individual Differences ◽  
D2 Receptor ◽  
D2 Receptors ◽  
Behavioral Differences ◽  
Biological Mechanisms ◽  
Brain Dopamine ◽  
Personality Dimension ◽  
Time Performance ◽  
Reaction Time Performance ◽  
Induced Changes

Recent research suggests that individual differences in brain dopamine (DA) functioning may be related to the personality dimension of extraversion. The present study was designed to further elucidate the biological mechanisms underlying behavioral differences between extraverts and introverts. For this purpose, the differential effects of a pharmacologically induced blockade of mesolimbocortical DA D2 receptors on reaction-time performance were investigated in 24 introverted and 24 extraverted subjects. Introverts were found to be much more susceptible to pharmacologically induced changes in D2 receptor activity than extraverts. This finding provides additional experimental evidence for the notion that individual differences in D2 receptor responsivity may represent a neurobiological substratum for the personality dimension of extraversion.

The Expression of Dopamine Receptors Gene and their Potential Role in Targeting Breast Cancer Cells with Selective Agonist and Antagonist Drugs. Could it be the Novel Insight to Therapy?

2019 ◽  
Vol 16 (2) ◽  
pp. 184-197 ◽  
Author(s):  
Hossein Bakhtou ◽  
Asiie Olfatbakhsh ◽  
Abdolkhaegh Deezagi ◽  
Ghasem Ahangari
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Cancer Cells ◽  
Dopamine Receptors ◽  
Breast Cancer Cells ◽  
D2 Receptors ◽  
Healthy Individuals ◽  
Agonist And Antagonist ◽  
The Mean ◽  
Mcf 7

Background:Breast cancer is one of the common causes of mortality for women in Iran and other parts of the world. The substantial increasing rate of breast cancer in both developed and developing countries warns the scientists to provide more preventive steps and therapeutic measures. This study is conducted to investigate the impact of neurotransmitters (e.g., Dopamine) through their receptors and the importance of cancers via damaging immune system. It also evaluates dopamine receptors gene expression in the women with breast cancer at stages II or III and dopamine receptor D2 (DRD2) related agonist and antagonist drug effects on human breast cancer cells, including MCF-7 and SKBR-3.Methods:The patients were categorized into two groups: 30 native patients who were diagnosed with breast cancer at stages II and III, with the mean age of 44.6 years and they were reported to have the experience of a chronic stress or unpleasant life event. The second group included 30 individuals with the mean age of 39 years as the control group. In order to determine the RNA concentration in all samples, the RNA samples were extracted and cDNA was synthesized. The MCF-7 cells and SKBR-3 cells were treated with dopamine receptors agonists and antagonists. The MTT test was conducted to identify oxidative and reductive enzymes and to specify appropriate dosage at four concentrations of dopamine and Cabergoline on MCF-7 and SKBR-3 cells. Immunofluorescence staining was done by the use of a mixed dye containing acridine orange and ethidiume bromide on account of differentiating between apoptotic and necrotic cells. Flow cytometry assay was an applied method to differentiate necrotic from apoptotic cells.Results:Sixty seven and thirty three percent of the patients were related to stages II and III, respectively. About sixty three percent of the patients expressed ER, while fifty seven percent expressed PR. Thirty seven percent of the patients were identified as HER-2 positive. All types of D2-receptors were expressed in PBMC of patients with breast cancer and healthy individuals. The expression of the whole dopamine receptor subtypes (DRD2-DRD4) was carried out on MCF-7 cell line. The results of RT-PCR confirmed the expression of DRD2 on SKBR-3 cells, whereas the other types of D2- receptors did not have an expression. The remarkable differences in gene expression rates between patients and healthy individuals were revealed in the result of the Real-time PCR analysis. The over expression in DRD2 and DRD4 genes of PBMCs was observed in the patients with breast cancer at stages II and III. The great amount of apoptosis and necrosis occurred after the treatment of MCF-7 cells by Cabergoline from 25 to 100 µmolL-1 concentrations.Conclusion:This study revealed the features of dopamine receptors associated with apoptosis induction in breast cancer cells. Moreover, the use of D2-agonist based on dopamine receptors expression in various breast tumoral cells could be promising as a new insight of complementary therapy in breast cancer.

The Effect of PAOPA, a Novel Allosteric Modulator of Dopamine D2 Receptors, on Select Signaling Proteins Following Sub-Chronic Administration in the Rat

2020 ◽  
Vol 13 ◽  
Author(s):  
Ritesh Daya ◽  
Joella Ho ◽  
Sharon Thomson ◽  
Jayant Bhandari ◽  
Ram K. Mishra
Keyword(s):  
Frontal Cortex ◽  
Mechanism Of Action ◽  
Dopamine D2 Receptor ◽  
D2 Receptor ◽  
Dorsal Striatum ◽  
D2 Receptors ◽  
Dopamine D2 ◽  
Therapeutic Mechanism ◽  
Clinical Models ◽  
G Protein Coupled

Background: Allosteric modulators of G-protein coupled receptors regulate receptor activity by binding to sites other than the active site and have emerged as a new and highly desirable class of drugs. PAOPA (3(R)-[(2(S)- pyrrolidinylcarbonyl)amino]-2-oxo-1-pyrrolidineacetamide), a peptidomimetic analog of Prolyl-Leucyl-Glycinamide, is a potent dopamine D2 receptor allosteric modulator. PAOPA has shown therapeutic effects in pre-clinical models of schizophrenia and extrapyramidal dysfunction. Objective: in this study, we sought to examine the biomolecular underpinnings of PAOPA‘s therapeutic outcomes in preclinical models of schizophrenia. Method: Following sub-chronic (daily for 7 days) administration of PAOPA, we assessed levels of dopamine D2 receptors, receptor kinases (GRK2 (G protein-coupled receptor kinase 2) and Arrestin-3), and phosphorylated mitogenactivated protein kinase (MAPKs), namely, extracellular signal-regulated kinases (ERK1/2) in the hippocampus, medial pre-frontal cortex, nucleus accumbens, pre-frontal cortex, and dorsal striatum via protein quantification. Results: Following 7 days of daily PAOPA treatment, we observed decreased GRK2 and increased dopamine D2 receptor expression in the dorsal striatum. These findings potentially underscore PAOPA’s therapeutic mechanism of action for the positive-like symptoms of schizophrenia in pre-clinical animal models. Additionally, we observed a decline in GRK2 in the hippocampus and an increase in phosphorylated ERK1 in the pre-frontal cortex, suggestive of a role for PAOPA in treating cognitive and/or affective dysfunction in pre-clinical models. Conclusion: While further studies are required to elucidate PAOPA’s mechanism of action, this study builds on prior investigations and develops an early framework to describe the therapeutic mechanism of action of PAOPA.

Estrogen Deficiency and Colonic Function: Surgical Menopause and Sex Differences in Angiotensin and Dopamine Receptor Interaction

2020 ◽  
Author(s):  
Pablo Garrido-Gil ◽  
Ana I Rodriguez-Perez ◽  
Lucia Lage ◽  
Jose L Labandeira-Garcia
Keyword(s):  
Sex Differences ◽  
Dopamine Receptors ◽  
D2 Receptor ◽  
Renin Angiotensin System ◽  
Receptor Expression ◽  
Oxidative Markers ◽  
Mutual Regulation ◽  
Inflammatory Processes ◽  
Angiotensin Type

Abstract The physiopathological mechanisms that regulate menopausal and sex differences in colonic transit, inflammatory processes, and efficacy of treatments have not been clarified. The dopaminergic system and renin–angiotensin system coexist in the gut and regulate different processes such as motility, absorption/secretion, and inflammation. We investigated the changes in expression of major angiotensin and dopamine receptors in the colon of male, female, and ovariectomized female mice. Possible interaction between both systems was investigated using male and female mice deficient (ko) for major angiotensin and dopamine receptors. In wild-type mice, colonic tissue from females showed lower angiotensin type 1/angiotensin type 2 ratio (an index of pro-inflammatory/anti-inflammatory renin–angiotensin system balance), lower dopamine D1 and D2 receptor expression, and lower levels of pro-inflammatory and pro-oxidative markers relative to males. Interestingly, ovariectomy increased the expression of pro-inflammatory angiotensin type 1 receptor expression and decreased anti-inflammatory angiotensin type 2 receptor expression, increased D1 and D2 receptor expression, and increased the levels of pro-inflammatory and pro-oxidative markers. Ovariectomy-induced changes were blocked by estrogen replacement. The present results suggest a mutual regulation between colonic angiotensin and dopamine receptors and sex differences in this mutual regulation. Estrogen regulates changes in both angiotensin and dopamine receptor expression, which may be involved in sex- and surgical menopause-related effects on gut motility, permeability, and vulnerability to inflammatory processes.

scholarly journals High dose antipsychotic polypharmacy and dopamine partial agonists - time to rethink guidelines?

2021 ◽  
pp. 026988112110264
Author(s):  
Gavin P Reynolds
Keyword(s):  
Side Effects ◽  
Dopamine D2 Receptor ◽  
D2 Receptor ◽  
Receptor Site ◽  
Receptor Occupancy ◽  
Antipsychotic Agents ◽  
High Dose ◽  
Partial Agonists ◽  
Favourable Side Effect Profile ◽  
Different Characteristics

Guidelines for the treatment of schizophrenia limit the use of antipsychotic agents to clinically-established maximum doses. This acknowledges both the absence of additional efficacy of dopamine D2 receptor antagonists above a receptor occupancy threshold, and the increases in side effects that can occur at higher doses. These limits restrict the dosing of combinations of antipsychotics as they do single agents; drugs sharing the major antipsychotic mechanism of D2 receptor antagonism will act additively in blocking these receptors. Several newer antipsychotic drugs, including aripiprazole and cariprazine, act as partial agonists at the D2 receptor site and avoid action at several other receptors, effects at which are responsible for some non-dopaminergic adverse effects. This pharmacology imparts different characteristics to the drugs resulting often in a more favourable side effect profile. Their partial agonism, along with high affinities for the D2 receptor, also means that these drugs given adjunctively may in part replace, rather than enhance, the D2 antagonism of other antipsychotic agents. This can result in an improvement in certain side effects without loss of antipsychotic efficacy. This article makes the case for distinguishing the D2 partial agonists from antagonists in defining maximum doses of combined treatments, which would increase the options available to the prescriber, emphasising that pharmacological mechanisms need to be understood in identifying optimal treatments for psychotic illness.

scholarly journals Effect of Zishenpingchan Granule on Neurobehavioral Manifestations and the Activity and Gene Expression of Striatal Dopamine D1 and D2 Receptors of Rats with Levodopa-Induced Dyskinesias

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Qing Ye ◽  
Xiao-Lei Yuan ◽  
Jie Zhou ◽  
Can-xing Yuan ◽  
Xu-ming Yang
Keyword(s):  
Gene Expression ◽  
Dopamine D2 Receptor ◽  
D2 Receptor ◽  
D2 Receptors ◽  
Striatal Dopamine ◽  
Control Group ◽  
Indirect Pathway ◽  
Dopamine D2 ◽  
D1 And D2 Receptors ◽  
Neurobehavioral Manifestations

This study was performed to observe the effects of Zishenpingchan granule on neurobehavioral manifestations and the activity and gene expression of striatal dopamine D1 and D2 receptors of rats with levodopa-induced dyskinesias (LID). We established normal control group, LID model group, and TCM intervention group. Each group received treatment for 4 weeks. Artificial neural network (ANN) was applied to excavate the main factor influencing variation in neurobehavioral manifestations of rats with LID. The results showed that overactivation in direct pathway mediated by dopamine D1 receptor and overinhibition in indirect pathway mediated by dopamine D2 receptor may be the main mechanism of LID. TCM increased the efficacy time of LD to ameliorate LID symptoms effectively mainly by upregulating dopamine D2 receptor gene expression.

2-Phenyl-4-(aminomethyl)imidazoles as Potential Antipsychotic Agents. Synthesis and Dopamine D2 Receptor Binding

1995 ◽  
Vol 38 (12) ◽  
pp. 2251-2255 ◽  
Author(s):  
Andrew Thurkauf ◽  
Alan Hutchison ◽  
John Peterson ◽  
Linda Cornfield ◽  
Robin Meade ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Dopamine D2 Receptor ◽  
D2 Receptor ◽  
Antipsychotic Agents ◽  
Dopamine D2

Dopamine D2 Receptor–Mediated Presynaptic Inhibition of Olfactory Nerve Terminals

2001 ◽  
Vol 86 (6) ◽  
pp. 2986-2997 ◽  
Author(s):  
Matthew Ennis ◽  
Fu-Ming Zhou ◽  
Kelly J. Ciombor ◽  
Vassiliki Aroniadou-Anderjaska ◽  
Abdallah Hayar ◽  
...  
Keyword(s):  
Olfactory Bulb ◽  
Dopamine D2 Receptor ◽  
Signal Transmission ◽  
D2 Receptor ◽  
Field Potential ◽  
Olfactory Nerve ◽  
D2 Receptors ◽  
Receptor Subtype ◽  
Juxtaglomerular Cells ◽  
Synaptic Responses

Olfactory receptor neurons of the nasal epithelium project via the olfactory nerve (ON) to the glomeruli of the main olfactory bulb, where they form glutamatergic synapses with the apical dendrites of mitral and tufted cells, the output cells of the olfactory bulb, and with juxtaglomerular interneurons. The glomerular layer contains one of the largest population of dopamine (DA) neurons in the brain, and DA in the olfactory bulb is found exclusively in juxtaglomerular neurons. D2 receptors, the predominant DA receptor subtype in the olfactory bulb, are found in the ON and glomerular layers, and are present on ON terminals. In the present study, field potential and single-unit recordings, as well as whole cell patch-clamp techniques, were used to investigate the role of DA and D2 receptors in glomerular synaptic processing in rat and mouse olfactory bulb slices. DA and D2 receptor agonists reduced ON-evoked synaptic responses in mitral/tufted and juxtaglomerular cells. Spontaneous and ON-evoked spiking of mitral cells was also reduced by DA and D2 agonists, and enhanced by D2 antagonists. DA did not produce measurable postsynaptic changes in juxtaglomerular cells, nor did it alter their responses to mitral/tufted cell inputs. DA also reduced 1) paired-pulse depression of ON-evoked synaptic responses in mitral/tufted and juxtaglomerular cells and 2) the amplitude and frequency of spontaneous, but not miniature, excitatory postsynaptic currents in juxtaglomerular cells. Taken together, these findings are consistent with the hypothesis that activation of D2 receptors presynaptically inhibits ON terminals. DA and D2 agonists had no effect in D2 receptor knockout mice, suggesting that D2 receptors are the only type of DA receptors that affect signal transmission from the ON to the rodent olfactory bulb.

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