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Vascular Effects of Endothelium-Derived Versus Hemoglobin-Transported Nitric Oxide in Healthy Subjects

This study has been completed.
Sponsor:
ClinicalTrials.gov Identifier:
NCT00001963
First Posted: December 10, 2002
Last Update Posted: March 4, 2008
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
Information provided by:
National Institutes of Health Clinical Center (CC)
  Purpose
Nitric oxide (NO) is a soluble gas, continuously synthesized by the endothelium, that contributes importantly to vasodilator tone of the coronary and systemic circulations by activating guanylyl cyclase in vascular smooth muscle, causing relaxation. Although regional synthesis of NO by the endothelium contributes to local vasodilator tone, Stamler and co-workers have proposed that regional vascular tone may also be regulated by NO transported from the lungs by hemoglobin as a consequence of enhanced binding of NO to reactive thiols of oxygenated hemoglobin. This study is designed to determine the contribution of hemoglobin-transported NO to forearm microvascular dilator tone in healthy subjects at rest and during regional hypoxia associated with forearm exercise stress, with measurements made before and after regional blockade of endothelial NO synthesis. Findings in this study may be relevant to understanding the physiological contribution and therapeutic potential of hemoglobin-transported NO in the regulation of vasodilator tone in diseases and conditions associated with regional endothelial dysfunction and reduced endothelial NO bioactivity (e.g., hypertension, diabetes mellitus, hypercholesterolemia, cigarette smoking, and estrogen deficiency).

Condition Intervention Phase
Diabetes Mellitus Healthy Hypercholesterolemia Hypertension Procedure: hemoglobin-transported nitric oxide Phase 1

Study Type: Interventional
Study Design: Primary Purpose: Treatment
Official Title: Vascular Effects of Endothelium-Derived Versus Hemoglobin-Transported Nitric Oxide in Healthy Subjects

Resource links provided by NLM:


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

Estimated Enrollment: 28
Study Start Date: December 1999
Estimated Study Completion Date: October 2000
Detailed Description:
Nitric oxide (NO) is a soluble gas, continuously synthesized by the endothelium, that contributes importantly to vasodilator tone of the coronary and systemic circulations by activating guanylyl cyclase in vascular smooth muscle, causing relaxation. Although regional synthesis of NO by the endothelium contributes to local vasodilator tone, Stamler and co-workers have proposed that regional vascular tone may also be regulated by NO transported from the lungs by hemoglobin as a consequence of enhanced binding of NO to reactive thiols of oxygenated hemoglobin. This study is designed to determine the contribution of hemoglobin-transported NO to forearm microvascular dilator tone in healthy subjects at rest and during regional hypoxia associated with forearm exercise stress, with measurements made before and after regional blockade of endothelial NO synthesis. Findings in this study may be relevant to understanding the physiological contribution and therapeutic potential of hemoglobin-transported NO in the regulation of vasodilator tone in diseases and conditions associated with regional endothelial dysfunction and reduced endothelial NO bioactivity (e.g., hypertension, diabetes mellitus, hypercholesterolemia, cigarette smoking, and estrogen deficiency).
  Eligibility

Information from the National Library of Medicine

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Ages Eligible for Study:   Child, Adult, Senior
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

All volunteer subjects must be between 21 and 75 years of age, in good health, and must have provided informed, written consent for participation in this study.

No subjects with a history or evidence of present or past hypertension (blood pressure greater than 145/95 mmHg), hypercholesterolemia (LDL cholesterol greater than 130 mg/dL), diabetes mellitus (fasting blood glucose greater than 120 mg/dL), smoking within 2 years, cardiac disease, peripheral vascular disease, coagulopathy, or any other disease predisposing to vasculitis or Raynaud's phenomenon.

No volunteer subject will be allowed to take any medication (oral contraceptive agents are allowed) or vitamin supplements for at least one month prior to study and will not be allowed to take aspirin for one week prior to study.

Pregnancy testing will be required of all women of reproductive age to exclude current pregnancy.

  Contacts and Locations
Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00001963


Locations
United States, Maryland
National Heart, Lung and Blood Institute (NHLBI)
Bethesda, Maryland, United States, 20892
Sponsors and Collaborators
National Heart, Lung, and Blood Institute (NHLBI)
  More Information

Publications:
ClinicalTrials.gov Identifier: NCT00001963     History of Changes
Other Study ID Numbers: 000031
00-H-0031
First Submitted: January 18, 2000
First Posted: December 10, 2002
Last Update Posted: March 4, 2008
Last Verified: November 1999

Keywords provided by National Institutes of Health Clinical Center (CC):
Blood Flow
Exercise
Microcirculation
S-nitrosohemoglobin
Vasodilation
Healthy Volunteer

Additional relevant MeSH terms:
Diabetes Mellitus
Hypercholesterolemia
Glucose Metabolism Disorders
Metabolic Diseases
Endocrine System Diseases
Hyperlipidemias
Dyslipidemias
Lipid Metabolism Disorders
Nitric Oxide
Bronchodilator Agents
Autonomic Agents
Peripheral Nervous System Agents
Physiological Effects of Drugs
Anti-Asthmatic Agents
Respiratory System Agents
Free Radical Scavengers
Antioxidants
Molecular Mechanisms of Pharmacological Action
Neurotransmitter Agents
Endothelium-Dependent Relaxing Factors
Vasodilator Agents
Gasotransmitters
Protective Agents