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.
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
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.
- Conditions
- Healthy, Hypercholesterolemia, Hypertension
- 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.
- First posted10 Dec 2002 (estimated)
- Study startFeb 1998
- Study completionJan 2001
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for HealthyStudies of the same condition, open and under way.
- More trials run by National Heart, Lung, and Blood Institute (NHLBI)The sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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
Sponsor and investigators
- Sponsor type
- US National Institutes of Health
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 116251Furchgott 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 6253831Taddei 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
Study at a glance
From the registry record, last updated by the sponsor on 4 Mar 2008. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Role of Cyclooxygenase Activity in the Endothelial Function of Hypertensive and Hypercholesterolemic Patients
- ClinicalTrials.gov ID
- NCT00001742
- Acronym / sponsor ID
- 980064
- Conditions
- Healthy, Hypercholesterolemia, Hypertension
- Keywords
- Acetylcholine, Aspirin, Nitric Oxide, Sodium Nitroprusside, Hypercholesterolemia, Hypertension
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 75 participants
- Lead sponsor
- National Heart, Lung, and Blood Institute (NHLBI)US National Institutes of Health
- Study start
- Feb 1998
- Study completion
- Jan 2001
- First posted
- 10 Dec 2002 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
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.
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.
Study design
Who may qualify
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult, Older adult
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Not reported in the source record.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 Mar 2008.
- Background: PubMed 116251Moncada 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.
- Background: PubMed 6253831Furchgott 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.
- Background: PubMed 9039114Taddei 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.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
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.