PET Imaging of Dopamine in Healthy Study Participants

This study has been completed.
Sponsor:
Information provided by:
National Institutes of Health Clinical Center (CC)
ClinicalTrials.gov Identifier:
NCT00062946
First received: June 17, 2003
Last updated: August 16, 2007
Last verified: August 2007
  Purpose

The purpose of this study is to measure molecules on or in cells that interact with a chemical in the nervous system, called dopamine. Investigators will obtain two kinds of images of the brain-a position emission tomography (PET) scan and a magnetic resonance imaging (MRI) scan.

Thirty-eight participants aged 18 to 45 will be enrolled in this study. They must have no history of medical or psychiatric illness, including substance abuse. Participants will have four appointments at NIH. On the first visit, they will undergo a physical exam, a medical history, and lab tests. The second and third visits will involve PET scans and the fourth visit will involve an MRI scan.

Participants will be compensated up to $430 for their involvement in this study.


Condition Intervention Phase
Healthy
Drug: (18F)fallypride
Phase 2

Study Type: Interventional
Study Design: Primary Purpose: Treatment
Official Title: PET Imaging of Dopamine D2 Receptors and Extracellular Dopamine With (18F)Fallypride, D-Amphetamine, and Alpha-Methyl-Para-Tyrosine in Healthy Subjects

Resource links provided by NLM:


Further study details as provided by National Institutes of Health Clinical Center (CC):

Estimated Enrollment: 45
Study Start Date: June 2003
Estimated Study Completion Date: August 2007
Detailed Description:

Abnormalities of dopaminergic function have been implicated in a number of neurological and psychiatric illnesses, including Parkinson's disease, schizophrenia, and psychostimulant dependence syndromes. Functional imaging with positron emission tomography (PET) and single photon emission computed tomography (SPECT) have demonstrated the feasibility of in vivo measurement of the distribution and the density of dopamine (DA) D1 and D2 receptors in humans. Besides simple measurement of receptor density, it has been shown that the competition between endogenous neurotransmitters and radiolabeled tracers might provide a tool to estimate extracellular levels of neurotransmitters. However, most of those studies have been confined to the striatum. In this protocol using a PET tracer (18F)fallypride, we will estimate both stimulant-induced DA release and baseline DA levels in the striatum and extrastriatal regions by comparing baseline scans and those after d-amphetamine or alpha-methyl-para-tryosine (AMPT) adminstration. In addition, to explore genetic factors that determine synaptic DA levels, allelic variations of two genes that regulate DA levels, catechol-O-methyltransferase and dopamine transporter, will be studied.

A recent study showed that oral administration of d-amphetamine induced displacement of (11C) raclopride in a similar way as the commonly used method of i.v. administration. The current protocol will be performed in two steps. First, the method of d-amphetamine administration will be determined by studying effects of oral d-amphetamine on the binding of (18F) fallypride binding. If oral administration effectively displaces the radioligand binding, this method will be applied in the subsequent study of examining effects of each of d-amphetamine and AMPT in individual subjects.

If this study successfully detects the influence of DA levels on (18F)fallypride binding, the same design will be applied to the studies of patients with psychiatric and neurological disorders.

  Eligibility

Ages Eligible for Study:   18 Years to 45 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria
  • INCLUSION CRITERIA:

Age 18-45, inclusive

In good general health on basis of history and physical examination

Normal screening laboratory studies including thyroid function tests, blood count, serum electrolytes, liver and kidney function, and urinalysis

Normal ECG at a resting condition

Normal blood pressure

No illegal drug use based on urine drug screen

EXCLUSION CRITERIA:

Pregnancy/Nursing

Evidence of active mental or neurological illness

Medically significant biochemical or hematological abnormality on screening laboratory studies

Abnormal ECG

High Blood Pressure (above 140 systolic and/or above 90 dystolic pressure)

History of myocardial infarction or angina pectoris

Positive urine drug screen or use of alcohol within one week prior to each PET study

History of substance abuse or dependence within 6 months

Presence of ferromagnetic metal in the body or heart pacemaker

Body weight more than 93 kg to limit AMPT dose to 4 g/ day (only for subjects having four PET scans and d-amphetamine and AMPT administration)

Claustrophobia

  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00062946

Locations
United States, Maryland
National Institutes of Health Clinical Center, 9000 Rockville Pike
Bethesda, Maryland, United States, 20892
Sponsors and Collaborators
  More Information

Publications:
ClinicalTrials.gov Identifier: NCT00062946     History of Changes
Other Study ID Numbers: 030104, 03-M-0104
Study First Received: June 17, 2003
Last Updated: August 16, 2007
Health Authority: United States: Federal Government

Keywords provided by National Institutes of Health Clinical Center (CC):
Thalamus
Cerebral Cortices
Quantification
Reproducibility
Dopamine Release
(18F) Fallypride
D-Amphetamine
Alpha-Methyl-Para-Tyrosine (AMPT)
PET
Dopamine D2 Receptor
Healthy Volunteer
HV

Additional relevant MeSH terms:
Amphetamine
Dextroamphetamine
Dopamine
Dopamine Agents
Alpha-Methyltyrosine
Central Nervous System Stimulants
Physiological Effects of Drugs
Pharmacologic Actions
Central Nervous System Agents
Therapeutic Uses
Sympathomimetics
Autonomic Agents
Peripheral Nervous System Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Adrenergic Agents
Adrenergic Uptake Inhibitors
Neurotransmitter Uptake Inhibitors
Dopamine Uptake Inhibitors
Cardiotonic Agents
Cardiovascular Agents
Protective Agents
Enzyme Inhibitors

ClinicalTrials.gov processed this record on August 28, 2014