Autonomic Nervous System and Nitric Oxide Interactions

This study is ongoing, but not recruiting participants.
Information provided by (Responsible Party):
Alfredo Gamboa, Vanderbilt University Identifier:
First received: June 1, 2010
Last updated: October 26, 2015
Last verified: October 2015
The investigators are interested in the role of the autonomic nervous system in the regulation of endothelial function. In particular, the investigators will study how endothelial function changes during autonomic withdrawal.

Condition Intervention
Endothelial Dysfunction
Drug: Trimethaphan
Drug: Placebo

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Crossover Assignment
Masking: Single Blind (Subject)
Official Title: The Autonomic Nervous System, Nitric Oxide and TPA Interactions

Resource links provided by NLM:

Further study details as provided by Vanderbilt University:

Primary Outcome Measures:
  • Endothelial Function [ Time Frame: 2 hours ] [ Designated as safety issue: No ]
    The dose response curve to intrabrachial vasodilators will be determined using the peak forearm blood flow during the last 5 minutes of each drug infusion

Secondary Outcome Measures:
  • Metabolic Parameters [ Time Frame: 2 hours ] [ Designated as safety issue: No ]
    During Insulin Clamp

  • Flow mediated dilatation [ Time Frame: 2 hours ] [ Designated as safety issue: No ]
    Changes in brachial artery diameter will be determined before and after autonomic blockade

Enrollment: 21
Study Start Date: June 2010
Estimated Study Completion Date: December 2015
Estimated Primary Completion Date: November 2015 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Trimethaphan
Response to intrabrachial vasodilators during autonomic withdrawal
Drug: Trimethaphan
Trimethaphan 4 mg/min IV, for the duration of the study (approximately 2 hours)
Other Name: Blocked
Placebo Comparator: Placebo
Response to intrabrachial vasodilators during saline intravenous (IV) infusion
Drug: Placebo
Response to intrabrachial vasodilators during IV saline infusion
Other Name: Intact


Ages Eligible for Study:   18 Years to 60 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes

For lean healthy volunteers:

  • 20 subjects (10 males and 10 females) aged 18-60 yr.
  • All potential volunteers will have routine blood test to screen for hepatic, renal, and hematological abnormalities.
  • Body mass index < 25Kg/m2 .
  • Female volunteers of childbearing potential will undergo HCG pregnancy test at screening and again on the study day.

For Obese subjects with metabolic syndrome.

  • 20 subjects (10 males and 10 females) aged 18-60 yr.
  • All potential volunteers will have routine blood test to screen for hepatic, renal, and hematological abnormalities.
  • Body mass index > 30Kg/m2.
  • Participants will be enrolled if they met at least three of the following criteria for metabolic syndrome (Expert panel, Jama 2001):

    • Waist circumference >102 cm in men and >88 cm in women
    • High fasting blood sugar (>110 mg%)
    • Triglyceride levels >150 mg%
    • Low high-density lipoprotein (HDL) cholesterol (<40 mg% for men; <50 mg% for women)
    • High blood pressure (systolic=130 and diastolic = 85 mmHg)
  • Female volunteers of childbearing potential will undergo serum HCG pregnancy test at screening and urine HCG pregnancy test again on the study day.

Exclusion criteria:

  • Pregnant females
  • Subjects unable to give voluntary informed consent
  • Subjects on anticoagulant drugs or anemic
  • Subjects with a recent medical illness
  • Subjects with a history of coronary heart disease
  • Subjects with known kidney or liver disease
  • Subjects with recent weight loss or consuming low carbohydrate diet
  Contacts and Locations
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Please refer to this study by its identifier: NCT01137253

United States, Tennessee
Vanderbilt University Medical Center
Nashville, Tennessee, United States, 37232
Sponsors and Collaborators
Vanderbilt University
  More Information

No publications provided

Responsible Party: Alfredo Gamboa, Research Assistant Professor, Vanderbilt University Identifier: NCT01137253     History of Changes
Other Study ID Numbers: 091489
Study First Received: June 1, 2010
Last Updated: October 26, 2015
Health Authority: United States: Institutional Review Board
United States: Food and Drug Administration

Keywords provided by Vanderbilt University:
Nitric Oxide
Autonomic Nervous System

Additional relevant MeSH terms:
Nitric Oxide
Trimethaphan camsylate
Adjuvants, Anesthesia
Anti-Asthmatic Agents
Antihypertensive Agents
Autonomic Agents
Bronchodilator Agents
Cardiovascular Agents
Central Nervous System Agents
Cholinergic Agents
Cholinergic Antagonists
Endothelium-Dependent Relaxing Factors
Free Radical Scavengers
Ganglionic Blockers
Molecular Mechanisms of Pharmacological Action
Neurotransmitter Agents
Nicotinic Antagonists
Peripheral Nervous System Agents
Pharmacologic Actions
Physiological Effects of Drugs
Protective Agents
Respiratory System Agents
Therapeutic Uses
Vasodilator Agents processed this record on November 25, 2015