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Sponsored by: |
National Institute of Mental Health (NIMH) |
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Information provided by: | National Institutes of Health Clinical Center (CC) |
ClinicalTrials.gov Identifier: | NCT00088738 |
This study is designed to observe the effects of a panic attack in patients with panic disorders and to demonstrate the involvement of Substance P in panic disorder, and thereby, further our understanding of its role in this illness. We will measure levels of Substance P in the brain by obtaining pictures of the brain using PET and MRI....
Condition | Intervention | Phase |
---|---|---|
Panic Disorder Healthy |
Drug: [18F] SPA-RQ |
Phase I |
Study Type: | Interventional |
Study Design: | Treatment |
Official Title: | Evaluation of Substance P Neurotransmission in Panic Disorder by PET Imaging of NK1 Receptors With [18F] SPA-RQ |
Estimated Enrollment: | 84 |
Study Start Date: | July 2004 |
Estimated Study Completion Date: | September 2008 |
The involvement of Substance P (SP) in depression and anxiety has been credibly demonstrated in a recent clinical trial. Although the precise physiological activation mechanism of the SP system is not yet known, the likelihood of exaggerated SP pathway activity in the pathogenesis of anxiety is supported in numerous animal studies that illustrate the anxiogenic, and anxiolytic effects of SP and SP antagonists (SPAs), respectively. Studies have further shown that SP release occurs in response to noxious, or aversive stimulation. SP stimulates NK1 receptors that then undergo endocytosis (i.e., internalization) resulting in a decrease in number of NK1 receptors on the cell surface. NK1 receptor quantification before, and after an aversive event, provides a dynamic measurement of SP neurotransmission.
In this protocol, we will use a new PET ligand that has demonstrated ability to serve as an NK1 receptor antagonist, [18F]SPA-RQ ( [18F]-labeled Substance P Antagonist Receptor Quantifier). Using this tracer, we will: 1.) quantify NK1 binding parameters and determine the reliability and reproducibility of these measures in 10 healthy controls, 2.) we will look for regional differences in NK1 receptor binding in 10 patients with panic disorder (PD) versus 10 normal controls, and 3.) We will perform a single-blind, placebo-controlled study to evaluate NK1 receptor binding in PD patients and controls following either saline or doxapram infusion, which is a respiratory stimulant, in 20 patients with panic disorder (PD) versus 20 normal controls. Doxapram acts on both peripheral and medullary chemoreceptors to increase the rate and depth of breathing. It appears to be a potent and specific panicogenic agent, triggering panic attacks. The majority of PD patients, but not controls, are expected to experience a panic attack (aversive event) following the doxapram infusion. Comparison of pre-panic and post-panic NK1 receptor binding in PD patients will provide an estimate of SP release. The goal of the present study is to demonstrate the involvement of SP in panic disorder, and thereby, further our understanding of its role in the psychopathology of this illness.
Ages Eligible for Study: | 18 Years to 65 Years |
Genders Eligible for Study: | Both |
Accepts Healthy Volunteers: | Yes |
EXCLUSION CRITERIA (Phase 1) Whole Body Imaging
INCLUSION CRITERIA: (Phase 2) Kinetic
EXCLUSION CRITERIA: (Phase 2) Kinetic
INCLUSION CRITERIA: (Phase 3A) Challenge
For Patients:
For Controls:
EXCLUSION CRITERIA: (Phase 3A) Challenge
For Patients and Controls:
INCLUSION CRITERIA: (Phase 3B) Comparative
For Patients:
For Controls:
EXCLUSION CRITERIA: (Phase 3B) Comparative
For Patients and Controls:
Study ID Numbers: | 040189, 04-M-0189 |
Study First Received: | July 30, 2004 |
Last Updated: | September 11, 2008 |
ClinicalTrials.gov Identifier: | NCT00088738 |
Health Authority: | United States: Federal Government |
Tachykinin Anxiety Neuroreceptor Internalization |
Carbon Dioxide Healthy Volunteer HV Panic Disorder |
Panic Disorder Anxiety Disorders Mental Disorders Healthy Substance P |
Pathologic Processes Disease |