Background:
Dopamine is a natural chemical in the brain that may influence eating behavior and physical activity. Researchers want to measure the brain s dopamine activity and understand how it differs in people with obesity.
Objective:
To better understand how brain function, particularly dopamine activity, relates to body weight and eating behavior.
Individuals may be able to participate if they:
Have a BMI of at least 18.5 kg/m2
Are weight-stable and generally healthy
Are between ages 18-45 years
Have normal blood pressure
Are not using illegal drugs (based on urine drug screen)
Are not following a special diet
Do not have metal implants
Design:
Participants will be screened with:
* Medical history
* Physical exam
* Questionnaires and an interview to see if it is safe to have a PET/MRI scan
* Fasting blood and urine tests
* Participants will eat a special diet given to them for the 5 days before their inpatient visit.
Participants will have a 5-day inpatient visit. Some days include blood and urine tests. Each day includes surveys and tests to measure habits and likes/dis-likes. A sample schedule may be:
Day 1: Participants will wear a monitor that uses a needle below the skin to measure glucose. Their body fat will be measured with low-dose x-rays
Day 2: Participants will have a PET scan. They will lie on a table that slides in and out of a donut-shaped scanner. They will be injected with a small amount of a radioactive substance and wear a cap on their head.
Day 3: Participants will have an MRI. They will lie on a table that slides in and out of a scanner.
Day 4: Participants will have another PET scan. This time, they will drink a milk shake during a break from the scanner. Then, they will go back inside the scanner for the end of their scan.
Day 5: Participants will wear a hood for up to 40 minutes to measure their breathing. They will also drink special water and collect samples of their urine to measure the rate they burn energy.
For 12 months after the visit, participants will track their weight and physical activity daily using a special scale and activity monitor. A few times over the year, the study team will send participants special activity monitors to use for 7 days at a time.
Participants will have an in-person 1-day follow-up visit. This includes most tests except for PET scanning....

开始日期2018-09-21

申办/合作机构

National Institute of Diabetes & Digestive & Kidney Diseases

NCT03190954

/ Recruiting早期临床1期IIT

Brain Dopaminergic Signaling in Opioid Use Disorders (OUD)

Background:
The chemical messenger dopamine carries signals between brain cells. It may affect addiction. Heavy use of pain medicines called opioids may decrease the amount of dopamine available to the brain. Researchers want to study if decreased dopamine decreases self-control and increases impulsiveness.
Objective:
To learn more about how opiate use disorder affects dopamine in the brain.
Eligibility:
Adults 18-80 years old who are moderate or severe opiate users
Healthy volunteers the same age
Design:
Participants will first be screened under another protocol. They will:
* Have a physical exam
* Answer questions about their medical, psychiatric, and alcohol and drug use history
* Take an MRI screening questionnaire
* Give blood and urine samples
* Have their breath tested for alcohol
Participants will have up to 3 study visits.
They will have 2-3 positron emission tomography (PET) scans. A radioactive chemical will be injected for the scans. Participants will lie on a bed that slides in and out of the donut-shaped scanner. A cap or plastic mask may be placed on the head.
Vital signs will be taken before and after the PET scans.
Participants will get capsules of placebo or the study drug. They will rate how they feel before, during and after.
Participants will have their breath and urine tested each day.
Participants will have magnetic resonance imaging (MRI) scans. They will lie on a table that slides into a cylinder in a strong magnetic field. They may do tasks on a computer screen while inside the scanner.
Participants will have tests of memory, attention, and thinking.
Participants will wear an activity monitor for one week....

开始日期2017-08-17

申办/合作机构

National Institute on Alcohol Abuse & Alcoholism

NCT00832221

/ Completed临床1期

An Open Label, 1-sequence Cross-over, Positron Emission Tomography (PET) Study With [11C]Raclopride to Determine Central D2 Dopamine Receptor Occupancy of Quetiapine Fumarate Immediate Release (SEROQUEL®) With Quetiapine Fumarate Extended Release (SEROQUEL XR®) in Healthy Male Volunteers

The aim of this study is to relate pharmacokinetics of two different formulations of quetiapine to PET measured receptor occupancy in the brains of healthy subjects.

开始日期2009-01-01

申办/合作机构

AstraZeneca PLC

100 项与 Raclopride 相关的临床结果

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100 项与 Raclopride 相关的转化医学

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100 项与 Raclopride 相关的专利（医药）

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2,144

项与 Raclopride 相关的文献（医药）

2025-08-01·NEUROPHARMACOLOGY

Kappa opioid receptors diminish spontaneous dopamine signals in awake mice through multiple mechanisms

Article

作者: Wallace, Conner W ; Holleran, Katherine M ; Slinkard, Clare Y ; Lapish, Christopher C ; Jones, Sara R ; Centanni, Samuel W

The role of the dynorphin/kappa opioid receptor (KOR) system in dopamine (DA) regulation has been extensively investigated. KOR activation reduces extracellular DA concentrations, but the exact mechanism(s) through which this is accomplished are not fully elucidated. To explore KOR influences on real-time DA fluctuations, we used the photosensor dLight1.2 with fiber photometry in the nucleus accumbens (NAc) core of freely moving male and female C57BL/6J mice. First, we established that the rise and fall of spontaneously arising DA signals were due to DA release and reuptake, respectively. Next, mice were systemically administered the KOR agonist U50,488H in the presence or absence of the KOR antagonist aticaprant. U50,488H reduced both the amplitude and width of spontaneous signals in both sexes. Further, the slope of the correlation between amplitude and width was increased, indicating that DA uptake rates were increased. U50,488H also reduced the frequency of occurrence of signals in males and females. The effects of KOR activation were stronger in males, while effects of KOR antagonism were stronger in females. Overall, KORs exerted significant inhibitory control over spontaneous DA signaling, acting through at least three mechanisms - inhibiting DA release, promoting DA transporter-mediated uptake, and reducing the frequency of signals.

2025-07-01·TOXICOLOGY AND APPLIED PHARMACOLOGY

The synthetic opioid isotonitazene induces locomotor activity and reward effects through modulation of the central dopaminergic system in mice

Article

作者: Tomiyama, Ken-Ichi ; Funada, Masahiko

Synthetic opioids, which differ from fentanyl, have recently emerged as new psychoactive substances and pose public health concerns. The pharmacological effects and drug dependency of these benzimidazole-based opioids, also known as nitazenes, remain unclear. In this study, we examined the selectivity of opioid receptors, effects on motor activity, and expression of reward effects for isotonitazene, which has been detected in many poisonings and fatalities since 2019. Isotonitazene was most selective for the μ-receptor and exhibited more potent agonist effects, with an EC₅₀ of 0.02 nM, than morphine (EC₅₀ = 34 nM) and fentanyl (EC₅₀ = 4.0 nM). In ICR mice, isotonitazene (up to 0.05 mg/kg) increased the locomotor activity in a dose-dependent manner. This effect was significantly suppressed by pretreatment with the opioid receptor antagonists naloxone (3 mg/kg) and β-FNA (1 mg/kg), the dopamine D1 receptor antagonist SCH23390 (0.5 mg/kg), and dopamine D2 receptor antagonist raclopride (6 mg/kg). The reward effects of isotonitazene, evaluated using conditioned place preference (CPP) in mice, showed that conditioning with isotonitazene produced significant dose-dependent CPP scores. Microdialysis analysis also confirmed that the isotonitazene dose that induced CPP (0.05 mg/kg) significantly increased dopamine levels in the nucleus accumbens of mice. These results suggest that isotonitazene, similar to fentanyl and morphine, is a compound with a high risk of forming drug dependence and reward effects via the dopaminergic nervous system. This study provides foundational data for biological evaluation of other nitazene compounds.

2025-05-01·PHARMACOLOGY BIOCHEMISTRY AND BEHAVIOR

Dopamine type II receptors in amygdala along with oxytocin in hypothalamus regulate social behavior in male mandarin voles

Article

作者: An, Xiaolei ; Chang, Gang ; Yu, Peng

The amygdala dopamine (DA) system and hypothalamic oxytocin (OT) play important roles in emotion regulation, and emotions are important in regulating social behavior. However, it is unclear whether DA in the amygdala is involved in the regulation of social behavior, and whether OT in the hypothalamus is also involved in this process. In this study, we examined the release of DA in the medial amygdala (MeA) during different social interactions and the effect of injecting the dopamine II receptor (D2R) agonist quinpirole and the D2R antagonist raclopride into the MeA on social behavior and OT in the paraventricular nucleus (PVN) and supraoptic nucleus (SON), as well as in the blood of male mandarin voles (Microtus mandarinus). The results showed that the DA in the MeA increased in the process of social behavior, and the DA in the face of strangers was higher than that in the face of familiars. In addition, the injection of D2R antagonists in the MeA reduced attacking and escaping behaviors but increased physical contact and investigating behaviors, increased the number of OT-IR neurons in the PVN and SON, and increased OT levels in the blood. While injection of D2R agonists in the MeA increased attacking and escaping behaviors but reduced physical contact and investigating behaviors, it also reduced OT-IR neurons in the SON. In conclusion, D2R in the medial amygdala and oxytocin in the hypothalamus regulate social behavior.

100 项与 Raclopride 相关的药物交易

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外链

KEGG	Wiki	ATC	Drug Bank
-	Raclopride	-	DB12518

研发状态

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适应症	最高研发状态	国家/地区	公司	日期
精神障碍	临床3期	欧盟	-	-

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研究	分期	人群特征	评价人数	分组	结果	评价	发布日期


NCT03648892 (CTgov)	早期临床1期	肥胖	61	[18F\]Fallypride+[11C\]Raclopride	膚廠蓋積構艱繭觸糧襯 = 壓糧齋膚鹽夢憲鏇衊襯鏇選積淵鬱網網糧製觸 (鬱鹹鹽網憲襯網鏇鬱廠, 鹽夢衊製築製鹽製糧鹽 ~ 製鹽積鑰範窪餘築製鹹) 更多	-	2023-05-03
EANM2016	N/A	-	-	[11C]raclopride	範醖襯願範鹹淵鬱鏇製(網範衊餘齋觸鏇鹹憲鏇) = 築鑰壓憲醖艱繭鏇憲餘構網築鏇夢鹹構鹹獵簾 (網憲遞製製觸艱壓選顧, 14.9)	-	2016-09-21