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HealthyNCT00001742

The Role of Cyclooxygenase Activity in the Endothelial Function of Hypertensive and Hypercholesterolemic Patients

An observational study of Healthy and Hypercholesterolemia, run by National Heart, Lung, and Blood Institute (NHLBI) at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

A layer of cells called the endothelium line the walls of blood vessels. These cells produce substances that control the tone of blood vessels and thus control blood flow through the vessel. Read more about this study

Who is it for?
Any ageHealthy volunteers can take part
Conditions the study is for
Healthy, Hypercholesterolemia, Hypertension
How many people
75 participants
Where
1 siteUnited States
Study dates
Feb 1998to Jan 2001
Phase
Observational
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages Any age
  • All sexes
  • Healthy volunteers accepted
  • Child, Adult, Older adult

Patients (men and nonpregnant women) with systemic hypertension and patients with hypercholesterolema will be included for this study.

Patient with aspirin allergies and those with a platelet count less than 50,000 will be excluded.

Volunteers cannot be in any kind of medication while participating in this study.

No history of diabetes, peripheral vascular disease, coagulopathy, or vasculitis.

Must be capable of rendering informed consent for all procedures.

Trial locations and contacts

1 site in 1 country.

United States1 site
  • National Heart, Lung and Blood Institute (NHLBI)

    Bethesda, Maryland, 20892

Other trials in United States

About this study

A layer of cells called the endothelium line the walls of blood vessels. These cells produce substances that control the tone of blood vessels and thus control blood flow through the vessel. This regulating activity of the endothelium is dysfunctional in several diseases of the heart and blood vessels, including high blood pressure and high levels of cholesterol.

Previous research has pointed toward a decrease in the action of nitric oxide (NO) as the cause of this abnormality. Nitric oxide is a substance produced by the cells of the endothelium that plays a role in the relaxation of blood vessels.

Read more

In this project researchers plan to study blood flow through the blood vessels in patients forearms after receiving four different drugs: sodium nitroprusside, acetylcholine, L-NMMA, and aspirin. These four drugs act on the blood vessels of the forearm through different mechanisms. Acetylcholine and sodium nitroprusside are drugs that open the blood vessels of the forearm and increase blood flow through the vessel. L-NMMA is a drug that blocks production of nitric oxide (NO). Aspirin's role in controlling blood flow is unknown.

Patients participating in this research study will not directly benefit from it. However, the study will contribute to researchers understanding of diseases of the blood vessels and heart.

Read the detailed description

The endothelium modulates vascular tone by the release of constricting and relaxing substances that act on the underlying smooth muscle. This regulatory activity of the endothelium is dysfunctional in a number of cardiovascular conditions, including essential hypertension and hypercholesterolemia. Previous studies from our group have implicated a decreased action of endothelium-derived nitric oxide (NO) as the mechanism responsible for this abnormality. Whether this reduced bioactivity of NO is related to vasoactive prostanoids remains uncertain.

We propose to test the hypothesis that an increased production of vasoactive prostanoids by the cyclooxygenase (COX) system is responsible for the reduced bioactivity of NO in essential hypertension and hypercholesterolemia. We will investigate the effect of COX inhibition by aspirin (ASA) on resting vascular tone, and on both endothelium-dependent and independent vasodilation in normal subjects, hypertensive patients, and hypercholesterolemic patients.

For this purpose, we propose to analyze the regional vascular responses to acetylcholine (ACH) and to sodium nitroprusside (SNP) before and after the administration of ASA. We will also analyze the basal forearm blood flow (FBF) responses to increasing doses of ASA infusion. We will employ infusion of drugs into the brachial artery and we will measure the responses of the forearm vasculature by means of strain gauge plethysmography.

Keywords
Acetylcholine, Aspirin, Nitric Oxide, Sodium Nitroprusside, Hypercholesterolemia, Hypertension
Medical subject headings
Hypercholesterolemia, Hypertension

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted10 Dec 2002 (estimated)
  2. Study startFeb 1998
  3. Study completionJan 2001

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Enrolment
75 participants
IDs, dates and publications
ClinicalTrials.gov ID
NCT00001742
Sponsor's protocol ID
980064
Other IDs
98-H-0064
Status last verified
Jan 2000
First submitted
3 Nov 1999
Last updated
4 Mar 2008
Results posted
No

Publications

  • Moncada S, Vane JR. Pharmacology and endogenous roles of prostaglandin endoperoxides, thromboxane A2, and prostacyclin. Pharmacol Rev. 1978 Sep;30(3):293-331. No abstract available.

    PubMed 116251
  • Furchgott RF, Zawadzki JV. The obligatory role of endothelial cells in the relaxation of arterial smooth muscle by acetylcholine. Nature. 1980 Nov 27;288(5789):373-6. doi: 10.1038/288373a0.

    PubMed 6253831
  • Taddei S, Virdis A, Ghiadoni L, Magagna A, Salvetti A. Cyclooxygenase inhibition restores nitric oxide activity in essential hypertension. Hypertension. 1997 Jan;29(1 Pt 2):274-9. doi: 10.1161/01.hyp.29.1.274.

    PubMed 9039114

Questions about this trial

What is this clinical trial studying?

An observational study of Healthy and Hypercholesterolemia, run by National Heart, Lung, and Blood Institute (NHLBI) at 1 site in United States.

The full registered description is in the About this study section and the official record.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 4 Mar 2008. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT00001742, which also lists 3 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 4 Mar 2008.

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