This site became the new on June 19th. Learn more.
Show more Menu IMPORTANT: Listing of a study on this site does not reflect endorsement by the National Institutes of Health. Talk with a trusted healthcare professional before volunteering for a study. Read more... Menu IMPORTANT: Talk with a trusted healthcare professional before volunteering for a study. Read more... Menu
Give us feedback

Dopamine in Orthostatic Tolerance

This study has been terminated.
(This study is being replaced by another protocol.)
Information provided by (Responsible Party):
Emily M. Garland, Vanderbilt University Identifier:
First received: September 5, 2008
Last updated: June 11, 2015
Last verified: June 2015
One goal of this study is to determine whether people with different amounts of dopamine-beta-hydroxylase (DBH) have different responses to events that affect blood pressure and heart rate. We will also study whether increasing dietary salt improves symptoms during upright posture. Finally, we will examine whether the dietary sodium level influences serum DBH activity and whether DBH level influences the response to sodium. DBH levels and the function of the sympathetic or involuntary nervous system will be assessed in normal volunteers and in patients with postural tachycardia syndrome (POTS).

Condition Intervention
Postural Tachycardia Syndrome Dietary Supplement: dietary sodium

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)
Primary Purpose: Supportive Care
Official Title: Dopamine in Orthostatic Tolerance

Resource links provided by NLM:

Further study details as provided by Emily M. Garland, Vanderbilt University:

Primary Outcome Measures:
  • plasma dopamine-beta-hydroxylase [ Time Frame: at enrollment and after tests ]
  • plasma dopamine [ Time Frame: after tests ]

Enrollment: 22
Study Start Date: November 2004
Study Completion Date: July 2012
Primary Completion Date: July 2012 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: A
10 mEq/day dietary sodium
Dietary Supplement: dietary sodium
10 mEq/day
Experimental: B
150 mEq/day dietary sodium
Dietary Supplement: dietary sodium
150 mEq/day dietary sodium
Experimental: C
300 mEq/day dietary sodium
Dietary Supplement: dietary sodium
300 mEq/day


Ages Eligible for Study:   18 Years to 60 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Upright plasma norepinephrine > 600 pg/ml, or
  • An increase in heart rate of > 30 beats per minute upon standing, and
  • Withdrawal of all medications for at least 3 days, and
  • No associated medical illness, and
  • Age 18 - 60 years old.

Exclusion Criteria:

  • Older than 60 years of age
  • Routinely taking medications affecting the autonomic nervous system
  • Any chronic illness (cardiac, pulmonary, endocrine, gastrointestinal, rheumatologic) other than POTS
  • Anemia (Hct < 30)
  • Women of childbearing age who are pregnant or nursing
  • Unable to give informed consent
  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 identifier: NCT00748228

United States, Tennessee
Vanderbilt University
Nashville, Tennessee, United States, 37232
Sponsors and Collaborators
Vanderbilt University
Principal Investigator: Emily M Garland, PhD Vanderbilt University
  More Information

Additional Information:
Responsible Party: Emily M. Garland, Research Assistant Professor, Vanderbilt University Identifier: NCT00748228     History of Changes
Other Study ID Numbers: 040769
Study First Received: September 5, 2008
Last Updated: June 11, 2015

Additional relevant MeSH terms:
Postural Orthostatic Tachycardia Syndrome
Arrhythmias, Cardiac
Heart Diseases
Cardiovascular Diseases
Pathologic Processes
Orthostatic Intolerance
Primary Dysautonomias
Autonomic Nervous System Diseases
Nervous System Diseases
Cardiotonic Agents
Autonomic Agents
Peripheral Nervous System Agents
Physiological Effects of Drugs
Dopamine Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Protective Agents processed this record on August 18, 2017