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Cells Jul 2022Dopamine and other neurotransmitters have the potential to induce neuroplasticity in the striatum via gene regulation. Dopamine receptor-mediated gene regulation relies...
Dopamine and other neurotransmitters have the potential to induce neuroplasticity in the striatum via gene regulation. Dopamine receptor-mediated gene regulation relies on second messenger cascades that involve cyclic nucleotides to relay signaling from the synapse to the nucleus. Phosphodiesterases (PDEs) catalyze cyclic nucleotides and thus potently control cyclic nucleotide signaling. We investigated the role of the most abundant striatal PDE, PDE10A, in striatal gene regulation by assessing the effects of PDE10A inhibition (by a selective PDE10A inhibitor, TP-10) on gene regulation and by comparing the basal expression of PDE10A mRNA throughout the striatum with gene induction by dopamine agonists in the intact or dopamine-depleted striatum. Our findings show that PDE10A expression is most abundant in the sensorimotor striatum, intermediate in the associative striatum and lower in the limbic striatum. The inhibition of PDE10A produced pronounced increases in gene expression that were directly related to levels of local PDE10A expression. Moreover, the gene expression induced by L-DOPA after dopamine depletion (by 6-OHDA), or by psychostimulants (cocaine, methylphenidate) in the intact striatum, was also positively correlated with the levels of local PDE10A expression. This relationship was found for gene markers of both D1 receptor- and D2 receptor-expressing striatal projection neurons. Collectively, these results indicate that PDE10A, a vital part of the dopamine receptor-associated second messenger machinery, is tightly linked to drug-induced gene regulation in the striatum. PDE10A may thus serve as a potential target for modifying drug-induced gene regulation and related neuroplasticity.
Topics: Dopamine; Dopamine Agonists; Gene Expression; Nucleotides, Cyclic; Phosphoric Diester Hydrolases; Receptors, Dopamine D1
PubMed: 35883657
DOI: 10.3390/cells11142214 -
British Journal of Clinical Pharmacology Feb 2009Rotigotine transdermal patch is a new non-ergolinic dopamine agonist developed for the treatment of Parkinson's disease and restless legs syndrome. Peripheral... (Clinical Trial)
Clinical Trial Randomized Controlled Trial
WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT
Rotigotine transdermal patch is a new non-ergolinic dopamine agonist developed for the treatment of Parkinson's disease and restless legs syndrome. Peripheral dopaminergic side-effects of dopamine agonists such as nausea and vomiting can be prevented by the antiemetic agent domperidone.
WHAT THIS STUDY ADDS
The study results show no evidence for an interaction of domperidone on bioavailability and steady-state pharmacokinetics of transdermal rotigotine. Co-administration of domperidone and rotigotine does not require dose adjustments for rotigotine transdermal patch.
AIMS
To evaluate the influence of the antiemetic agent domperidone on steady-state pharmacokinetics, safety and tolerability of multiple-dose treatment of the transdermally applied non-ergolinic dopamine agonist rotigotine.
METHODS
Sixteen healthy male subjects (mean age 30.3 years) participated in a randomized, two-way crossover clinical trial. Treatment A consisted of transdermal rotigotine patch (2 mg (24 h)(-1), 10 cm(2), total drug content 4.5 mg) applied daily for 4 days, and concomitant oral domperidone (10 mg t.i.d.) for 5 days. For treatment B, subjects received only transdermal rotigotine treatment (daily for 4 days). Pharmacokinetic variables describing systemic exposure and renal elimination of rotigotine and metabolites, and safety and tolerability of the treatment were assessed.
RESULTS
The primary steady-state pharmacokinetic parameters (C(max,ss) and AUC((0-24),ss)) were similar with or without co-administration of domperidone. Geometric mean ratios were close to 1 and respective 90% confidence intervals were within the acceptance range of bioequivalence (0.8, 1.25): C(max,ss) 0.96 (0.86, 1.08) and AUC((0-24),ss) 0.97 (0.87, 1.08). t(max,ss), t(1/2), secondary parameters calculated on days 4/5 after repeated patch application (C(min,ss), C(ave,ss), AUC((0-tz))) and renal elimination for unconjugated rotigotine and its metabolites were also similar with and without comedication of domperidone. A reduction in the dopaminergic side-effect nausea was seen with domperidone comedication.
CONCLUSIONS
No changes of pharmacokinetic parameters describing systemic exposure and renal elimination of rotigotine were observed when domperidone was administered concomitantly with rotigotine. The lack of pharmacokinetic interactions indicates that a dose adjustment of rotigotine transdermal patch is not necessary with concomitant use of domperidone.
Topics: Administration, Cutaneous; Adolescent; Adult; Cross-Over Studies; Domperidone; Dopamine Agonists; Dose-Response Relationship, Drug; Drug Interactions; Drug Therapy, Combination; Humans; Male; Middle Aged; Tetrahydronaphthalenes; Thiophenes; Treatment Outcome; Young Adult
PubMed: 19094160
DOI: 10.1111/j.1365-2125.2008.03334.x -
CNS Neuroscience & Therapeutics 2008Developing effective treatments for chronic neurodegenerative disorders such as amyotrophic lateral sclerosis (ALS) has proven extremely difficult. ALS is universally... (Review)
Review
Developing effective treatments for chronic neurodegenerative disorders such as amyotrophic lateral sclerosis (ALS) has proven extremely difficult. ALS is universally fatal, characterized by progressive weakness due to the degeneration of upper and lower motor neurons, and leads eventually to respiratory failure which is the usual cause of death. Only a single treatment has been approved, the modestly effective nonspecific neuroprotectant Rilutek (riluzole; 2-amino-6-(trifluoromethoxy)benzothiazole). KNS-760704 [(6R)-4,5,6,7-tetrahydro-N6-propyl-2,6-benzothiazole-diamine dihydrochloride, RPPX], a synthetic amino-benzothiazole with demonstrated activity in maintaining mitochondrial function, is being developed as a treatment for ALS. It has proven to be effective in multiple in vitro and in vivo assays of neuroprotection, including the G93A-SOD1 mutant mouse model; however, its specific mechanism of action remains unknown. The potential of KNS-760604 as a treatment for ALS was first suggested by studies showing that its optical enantiomer, Mirapex[(6S)-4,5,6,7-tetrahydro-N6-propyl-2,6-benzothiazole-diamine; pramipexole dihydrochloride; PPX], a high-affinity agonist at dopamine D2, D3, and D4 receptors, exhibits important neuroprotective properties independent of its dopamine receptor agonism. In cell-based assays, both RPPX and PPX reduce the production of reactive oxygen species (ROS), attenuate the activation of apoptotic pathways, and increase cell survival in response to a variety of neurotoxins. However, PPX has limited utility as a clinical neuroprotective agent because the drug concentrations required for neuroprotection would likely produce unacceptable dopaminergic side effects. RPPX, on the other hand, while possessing the same neuroprotective potential as PPX, is a much lower-affinity dopamine receptor agonist and may therefore be more useful in the treatment of ALS. This review will examine the data supporting the hypothesis that the RPPX may have therapeutic potential for the treatment of neurodegenerative disorders including ALS. In addition, we will briefly review recent preclinical data in support of RPPX, and discuss the current status of its clinical development.
Topics: Amyotrophic Lateral Sclerosis; Animals; Benzothiazoles; Dopamine Agonists; Humans; Mitochondria; Neuroprotective Agents; Pramipexole; Stereoisomerism
PubMed: 18801114
DOI: 10.1111/j.1755-5949.2008.00048.x -
Journal of Clinical Psychopharmacology Feb 2016In the last 10 years, dopamine replacement therapy (DRT) has become a well-known risk factor for developing an impulse control disorder, such as gambling disorder (GD).... (Review)
Review
BACKGROUND
In the last 10 years, dopamine replacement therapy (DRT) has become a well-known risk factor for developing an impulse control disorder, such as gambling disorder (GD). Another medication, aripiprazole (ARI), has been more recently identified as another risk factor. Dopamine replacement therapy and ARI share a dopamine agonist action. Our work aimed at comparing patients with PG according to their treatment with DRT or ARI.
METHODS
Two methods were combined-a systematic review concentrated on case reports and the analysis of a French disordered gamblers cohort focused on patients using ARI or DRT at inclusion.
RESULTS
We reported 48 cases of GD possibly due to DRT and 17 cases of GD possibly due to ARI. Because of their standardized assessment, only the EVALJEU patients could be compared. Two clinical patterns emerged. Patients in the ARI group were young, impulsive, and high novelty seekers and had a history of substance misuse. Their first gambling experience occurred during adolescence. Conversely, patients in the DRT group were old, and they began gambling late in life. They showed low levels of gambling-related cognition.
CONCLUSIONS
Patients in the ARI group seemed to be more severe pathological gamblers than patients in the DRT group. Aripiprazole is a partial D2 receptor agonist, whereas DRT includes full D2 receptor agonist. The trigger mechanism of PG development is complex and cannot only be attributed only to the pharmacodynamic effects of dopaminergic drugs. Indeed, individual vulnerability factors and environmental factors need to be considered.
Topics: Adolescent; Aripiprazole; Disruptive, Impulse Control, and Conduct Disorders; Dopamine Agonists; Gambling; Humans; Receptors, Dopamine D2; Risk Factors
PubMed: 26658263
DOI: 10.1097/JCP.0000000000000444 -
Clinical Interventions in Aging 2009Ropinirole prolonged release is a once-daily, 24-hour formulation of ropinirole, a non-ergot dopamine agonist. It is approved as monotherapy and as an adjunct to... (Review)
Review
Ropinirole prolonged release is a once-daily, 24-hour formulation of ropinirole, a non-ergot dopamine agonist. It is approved as monotherapy and as an adjunct to levodopa in the treatment of Parkinson's disease (PD). Several potential advantages of ropinirole prolonged release compared to the immediate release formulation include maintaining more consistent dopaminergic activity with steadier plasma levels, increased tolerability, greater compliance from a simpler once-daily dosing regimen and ease in dose titration. In a randomized, double-blind, non-inferiority, crossover study, ropinirole prolonged release was shown to have comparable efficacy and tolerability to immediate release ropinirole in early PD patients, with significantly greater compliance. Subjects were converted overnight between ropinirole formulations without loss of efficacy and with good tolerability. In a randomized, double-blind, placebo-controlled study in advanced PD, daily "off" time was reduced by an average of 2.1 hours with ropinirole prolonged release compared to 0.4 hours with placebo. Patients on ropinirole prolonged release were also more likely to require less daily levodopa. Ropinirole prolonged release is well tolerated with a similar adverse effect profile to other non-ergot dopamine agonists. The most common adverse effects include dyskinesia, nausea, dizziness, hallucinations, somnolence, abdominal pain or discomfort and orthostatic hypotension. Ropinirole prolonged release is a safe and effective treatment option for both early and advanced PD. This manuscript briefly reviews the current pharmacological treatment options for PD and provides a more detailed review of the currently available data regarding ropinirole prolonged release as a treatment option for PD.
Topics: Delayed-Action Preparations; Dopamine Agonists; Dose-Response Relationship, Drug; Humans; Indoles; Parkinson Disease; Treatment Outcome
PubMed: 19503779
DOI: 10.2147/cia.s3358 -
The Journal of Pharmacology and... Aug 2022Methylphenidate is used widely to treat symptoms of attention-deficit/hyperactivity disorder (ADHD), but like other stimulants has significant side effects. This study...
Methylphenidate is used widely to treat symptoms of attention-deficit/hyperactivity disorder (ADHD), but like other stimulants has significant side effects. This study used a rodent model (spontaneously hypertensive rat) of spatial working memory (sWM) to compare the effects of methylphenidate with the novel dopamine D-like receptor agonist 2-methyldihydrexidine. Acute oral administration of methylphenidate (1.5 mg/kg) caused sWM improvement in half of the tested rats, but impairment in the others. Both improvement or impairment were eliminated by administration of the D antagonist SCH39266 directly into the prefrontal cortex (PFC). Conversely, 2-methyldihydrexidine showed greater sWM improvement compared with methylphenidate without significant impairment in any subject. Its effects correlated negatively with vehicle-treated baseline performance (i.e., rats with lower baseline performance improved more than rats with higher baseline performance). These behavioral effects were associated with neural activities in the PFC. Single neuron firing rate was changed, leading to the alteration in neuronal preference to correct or error behavioral responses. Overall, 2-methyldihydrexidine was superior to methylphenidate in decreasing the neuronal preference, prospectively, in the animals whose behavior was improved. In contrast, methylphenidate, but not 2-methyldihydrexidine, significantly decreased neuronal preference, retrospectively, in those animals who had impaired performance. These results suggest that a D agonist may be more effective than methylphenidate in regulating sWM-related behavior through neural modulation of the PFC, and thus may be superior to methylphenidate or other stimulants as ADHD pharmacotherapy. SIGNIFICANCE STATEMENT: Methylphenidate is effective in ADHD by its indirect agonist stimulation of dopamine and/or adrenergic receptors, but the precise effects on specific targets are unclear. This study compared methylphenidate to a dopamine D receptor-selective agonist by investigating effects on working memory occurring via neural modulation in the prefrontal cortex. The data suggest that pharmacological treatment selectively targeting the dopamine D may offer a superior approach to ADHD pharmacotherapy.
Topics: Animals; Attention Deficit Disorder with Hyperactivity; Central Nervous System Stimulants; Dopamine; Dopamine Agonists; Memory, Short-Term; Methylphenidate; Prefrontal Cortex; Rats; Receptors, Dopamine D1; Retrospective Studies
PubMed: 35661631
DOI: 10.1124/jpet.122.001215 -
The European Journal of Neuroscience Jan 2017The incidence of pathological gambling in Parkinson's patients is significantly greater than in the general population. A correlation has been observed between dopamine... (Review)
Review
The incidence of pathological gambling in Parkinson's patients is significantly greater than in the general population. A correlation has been observed between dopamine agonist medication and the development of pathological gambling. However, scientists conjecture that the affected patients have underlying risk factors. Studies analysing Parkinson's patients have detected that patients who developed pathological gambling are younger, score higher on novelty-seeking tests, are more impulsive and are more likely to have a personal or family history of alcohol addiction. In addition, some genetic variations have been associated with the susceptibility of developing pathological gambling, which include mutations of DRD3, 5-HTTLPR and GRIN2B. Studies focusing on neurofunctional discrepancies between Parkinson's patients with and without pathological gambling have found increased functional activation and dopamine release in regions associated with the mesolimbic reward system. Furthermore, there is also evidence showing increased processing of reward and decreased activation elicited by punishment, suggesting altered learning processes. Furthermore, the role of deep brain stimulation of the nucleus subthalamicus (STN DBS) is controversial. In most Parkinson's patients, pathological gambling resolved after the initiation of the STN DBS, which might be explained by discontinuation or decrease in dopamine agonist medication. However, it has been also shown that some patients are more impulsive while the STN DBS is activated. These differences may depend on the DBS localization in the more limbic or motor part of the STN and their regulative effects on impulsivity. Further research is needed to clarify susceptibility factors for the development of pathological gambling in Parkinson's patients.
Topics: Animals; Deep Brain Stimulation; Dopamine Agents; Dopamine Agonists; Humans; Impulsive Behavior; Parkinson Disease; Risk Factors
PubMed: 27623191
DOI: 10.1111/ejn.13396 -
Nicotine & Tobacco Research : Official... Jun 2018Dopaminergic functioning is thought to play critical roles in both motivation and addiction. There is preliminary evidence that dopamine agonists reduce the motivation...
BACKGROUND
Dopaminergic functioning is thought to play critical roles in both motivation and addiction. There is preliminary evidence that dopamine agonists reduce the motivation for cigarettes in smokers. However, the effects of pramipexole, a dopamine D3 receptor preferring agonist, have not been investigated. The aim of this study was to examine the effects of an acute dose of pramipexole on the motivation to earn cigarettes and nondrug rewards.
METHODS
Twenty dependent and 20 occasional smokers received 0.5 mg pramipexole using a double-blind, placebo-controlled crossover design. Motivation for cigarettes and consummatory nondrug rewards was measured using the DReaM-Choice task, in which participants earned, and later "consumed," cigarettes, music, and chocolate. Demand for cigarettes was measured using the Cigarette Purchase Task (CPT). Self-reported craving, withdrawal, and drug effects were also recorded.
RESULTS
Dependent smokers chose (p < .001) and button-pressed for (p < .001) cigarettes more, and chose chocolate less (p < .001), than occasional smokers. Pramipexole did not affect the number of choices for or amount of button-pressing for any reward including cigarettes, which was supported by a Bayesian analysis. The dependent smokers had greater demand for cigarettes than occasional smokers across all CPT outcomes (ps < .021), apart from elasticity. Pramipexole did not affect demand for cigarettes, and this was supported by Bayesian analyses. Pramipexole produced greater subjective "feel drug" and "dislike drug" effects than placebo.
CONCLUSIONS
Dependent and occasional cigarette smokers differed in their motivation for cigarettes but not for the nondrug rewards. Pramipexole did not acutely alter motivation for cigarettes. These findings question the role of dopamine D3 receptors in cigarette-seeking behavior in dependent and occasional smokers.
IMPLICATIONS
This study adds to the growing literature about cigarette versus nondrug reward processing in nicotine dependence and the role of dopamine in cigarette-seeking behavior. Our results suggest nicotine dependence is associated with a hypersensitivity to cigarette rewards but not a hyposensitivity to nondrug rewards. Furthermore, our results question the importance of dopamine D3 receptors in motivational processing of cigarettes in occasional and dependent smokers.
Topics: Adult; Behavior, Addictive; Cigarette Smoking; Craving; Cross-Over Studies; Dopamine Agonists; Double-Blind Method; Female; Humans; Male; Motivation; Pramipexole; Receptors, Dopamine D3; Tobacco Use Disorder; Young Adult
PubMed: 29065193
DOI: 10.1093/ntr/ntx159 -
The Yale Journal of Biology and Medicine Mar 2016Dopamine agonists (DA) are therapeutic agents that are commonly used in the treatment of Parkinson's disease (PD). They can reduce undesired motor fluctuations and delay... (Review)
Review
Dopamine agonists (DA) are therapeutic agents that are commonly used in the treatment of Parkinson's disease (PD). They can reduce undesired motor fluctuations and delay the administration of levodopa therapy. However, this drug family is associated with specific side effects that can significantly diminish the quality of life among PD patients. Some of them impose significant risks for individuals who have a history of cardiovascular diseases, psychosis, and depression, or those older patients who suffer from renal or hepatic insufficiency. Various pharmacokinetic and pharmacodynamic considerations need to be taken into account when administering DA therapy. The goal of this review is to provide a comprehensive, up-to-date overview of DA therapeutic modalities for PD.
Topics: Dopamine Agonists; Humans; Parkinson Disease; Patient Safety; Quality of Life
PubMed: 27505015
DOI: No ID Found -
Archives of Endocrinology and Metabolism Apr 2024Dopamine agonists are the first line of treatment for patients with symptomatic hyperprolactinemia due to prolactinomas and in those with idiopathic hyperprolactinemia....
Treatment of hyperprolactinemia in women: A Position Statement from the Brazilian Federation of Gynecology and Obstetrics Associations (Febrasgo) and the Brazilian Society of Endocrinology and Metabolism (SBEM).
Dopamine agonists are the first line of treatment for patients with symptomatic hyperprolactinemia due to prolactinomas and in those with idiopathic hyperprolactinemia. Treatment with these agents is effective in 80%-90% of the cases. Infertility treatment of patients with hyperprolactinemia is also carried out with dopamine agonists, aiming for the normalization of prolactin levels. The risk of symptomatic growth of prolactinomas during pregnancy is dependent on the tumor's size, duration of previous treatments, and prolactin levels. Notably, the corresponding risk is relatively low in cases of microprolactinomas (<5%). Remission of hyperprolactinemia occurs in about 30% of the patients after drug treatment and may also occur after pregnancy and menopause. The use of some drugs, such as antidepressants and antipsychotics, is a frequent cause of hyperprolactinemia, and managing this occurrence involves unique considerations. This position statement by the Brazilian Federation of Gynecology and Obstetrics Associations (Febrasgo) and Brazilian Society of Endocrinology and Metabolism (SBEM) addresses the recommendations for measurement of serum prolactin levels and the investigations of symptomatic and asymptomatic hyperprolactinemia and drug-induced hyperprolactinemia in women.
Topics: Pregnancy; Humans; Female; Hyperprolactinemia; Prolactinoma; Dopamine Agonists; Prolactin; Pituitary Neoplasms; Brazil
PubMed: 38578473
DOI: 10.20945/2359-4292-2023-0504