Brain Receptors in Sympathetic Nervous System Regulation

NCT00029627 | Completed

• 2 other identifiers: 02008902-M-0089
• Study Type: observational
• Target: 200
• Locations: 1 country
• Sites: 1

Brief Summary

The purpose of this study is to investigate the role of brain receptors called alpha2-adrenoreceptors in regulating the sympathetic nervous system, which maintains the supply of blood and fuel to the body's organs in times of stress, fear, anger, or exercise. Alpha(2)-adrenergic receptors (alpha(2)-AR) play a role in a variety of physiological functions. There are three subtypes of alpha(2)-ARs, and their differences are unknown. This study will examine the functional roles of these three subtypes by comparing the behavioral, biochemical, psychophysiological, and autonomic function effects of the alpha(2)-AR drugs clonidine and yohimbine. Participants in this study will undergo a physical examination, electrocardiogram (ECG), and blood, urine, and saliva tests. Women will have hormone tests to determine the time of their last period and the time of their next ovulation. Participants will undergo neuropsychological testing and other procedures.

Conditions

Healthy

Keywords

Alpha2-Adrenoreceptors; Polymorphisms; Challenge Study; Yohimbine; Clonidine; Subtypes; Normal Control; HV; Healthy Volunteer

Interventions

Yohimbine DRUG

Eligibility Criteria

• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• Healthy subjects with a negative first-degree family history of psychiatric disorders as determined by the Family Interview of Genetic Studies are eligible.
• Subjects must be willing to participate in a challenge study.
• Subjects must be in good physical health.
• Subjects must have the absence of any Axis I and Axis II DSM-IV diagnosis.
• Subjects will be excluded if they have evidence for an axis I psychiatric disorder or the presence of an axis II personality disorder.
• Smokers are ineligible to participate.
• Subjects with recent life stressors (3 months) or chronic life stressors (1 year) will be ineligible.
• Subjects must be between the ages of 18 and 50.
• Subjects must meet criteria for one of 6 genotypically defined subgroups.
• Subjects must not have taken antidepressant or other medications likely to alter monoamine neurochemistry or cerebrovascular and cardiovascular function for at least 6 months prior to the challenge studies.

You may not qualify if:

• Subjects will be excluded if they have medical or neurological illnesses likely to affect physiology or anatomy, i.e. hypertension, cardiovascular disorders.
• Subjects must not have a history of drug (including BZDs) or alcohol abuse within 1 year or a lifetime history of alcohol or drug dependence.
• Subjects with current or previous regular use (greater than 4 weeks) of BZDs and excessive use of alcohol (greater than 8 ounces/week for men and greater than 6 ounces/week for women) in the past or present are ineligible to participate.
• Women who are currently pregnant or breastfeeding are not eligible.
• Subjects who cannot hear a 40 dB(HL) pure tone in the 1000- to 4000 Hz span (Welsh Allen audioscope) will be excluded from studies.

Sponsors & Collaborators

• National Institute of Mental Health (NIMH): lead

Study Sites (1)

National Institute of Mental Health (NIMH)

Bethesda, Maryland, 20892, United States

Location

Related Publications (3)

• Eisenhofer G, Esler MD, Meredith IT, Dart A, Cannon RO 3rd, Quyyumi AA, Lambert G, Chin J, Jennings GL, Goldstein DS. Sympathetic nervous function in human heart as assessed by cardiac spillovers of dihydroxyphenylglycol and norepinephrine. Circulation. 1992 May;85(5):1775-85. doi: 10.1161/01.cir.85.5.1775.

  PMID: 1572033 BACKGROUND

• O'Dowd BF, Lefkowitz RJ, Caron MG. Structure of the adrenergic and related receptors. Annu Rev Neurosci. 1989;12:67-83. doi: 10.1146/annurev.ne.12.030189.000435.

  PMID: 2648960 BACKGROUND

• Venter JC, Fraser CM, Kerlavage AR, Buck MA. Molecular biology of adrenergic and muscarinic cholinergic receptors. A perspective. Biochem Pharmacol. 1989 Apr 15;38(8):1197-208. doi: 10.1016/0006-2952(89)90325-0. No abstract available.

  PMID: 2650684 BACKGROUND

MeSH Terms

Interventions

Yohimbine

Intervention Hierarchy (Ancestors)

Secologanin Tryptamine Alkaloids; Indole Alkaloids; Alkaloids; Heterocyclic Compounds; Indoles; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Indolizidines; Indolizines

Study Design

• Study Type: observational
• Sponsor Type: NIH

Study Record Dates

• First Submitted: January 16, 2002
• First Posted: January 17, 2002
• Study Start: January 1, 2002
• Study Completion: December 1, 2004
• Last Updated: March 4, 2008

Record last verified: 2004-12

Locations

US (1)