Study of Inherited Changes of Receptors Located on Blood Vessels - Full Text View

Sponsored by:	National Heart, Lung, and Blood Institute (NHLBI)
Information provided by:	National Institutes of Health Clinical Center (CC)
ClinicalTrials.gov Identifier:	NCT00001741

Purpose

The renin angiotensin system is a complex process involving hormones and enzymes that regulate blood volume and blood pressure. The hormone angiotensin II is responsible for making blood vessels narrow or constrict. Angiotensin II is found in the blood and can attach to special sites called receptors on blood vessel walls. These receptors are programmed to accept angiotensin II and cause a constriction of the blood vessel. This function is found in the genetic information of each individual person.

Occasionally patients have changes in their genes related to angiotensin II receptors. These changes may result in the receptors acting differently to angiotensin II, which may affect the function of blood vessels.

This study is designed to improve researchers understanding of the physiological effects on blood vessels associated with mutations of the genes responsible for angiotensin II receptor function.

Condition	Intervention	Phase
Cardiovascular Disease	Drug: Losartan	Phase I

Drug Information available for: Losartan Losartan potassium Angiotensin II Angiotensin II, ile(5)-

U.S. FDA Resources

Study Type:	Interventional
Study Design:	Treatment, Safety Study
Official Title:	Study of Vascular Responsiveness in Subjects With Polymorphisms of the Angiotensin II Type I Receptor Gene

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

Estimated Enrollment:	200
Study Start Date:	November 1997
Estimated Study Completion Date:	April 2003

Detailed Description:

Polymorphisms in the genes encoding for various elements of the renin angiotensin system have been associated with cardiovascular disease. We have isolated novel alleles in the angiotensin II type I receptor gene. We propose this exploratory investigation to study the physiological effect of these mutations on vascular function in patients and family members who carry these rare alleles.

Eligibility

Genders Eligible for Study:	Both
Accepts Healthy Volunteers:	Yes

Criteria

Patients aged 21 or older with chronic orthostatic intolerance will be included.

There will be no exclusion from participation in the study on the basis of ethnicity/race.

Patients will be recruited in the Cardiology Branch outpatient clinic, Dr. David Goldstein (Chief Neurocardiology Section, NINDS, NIH), or from outside physicians.

Children will be excluded from the study because of inability in obtaining informed consent.

Cognitively impaired individuals, prisoners, or other institutionalized persons will not be able to participate.

Contacts and Locations

Please refer to this study by its ClinicalTrials.gov identifier: NCT00001741

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:

Rigat B, Hubert C, Alhenc-Gelas F, Cambien F, Corvol P, Soubrier F. An insertion/deletion polymorphism in the angiotensin I-converting enzyme gene accounting for half the variance of serum enzyme levels. J Clin Invest. 1990 Oct;86(4):1343-6.

Cambien F, Poirier O, Lecerf L, Evans A, Cambou JP, Arveiler D, Luc G, Bard JM, Bara L, Ricard S, et al. Deletion polymorphism in the gene for angiotensin-converting enzyme is a potent risk factor for myocardial infarction. Nature. 1992 Oct 15;359(6396):641-4.

Alderman MH, Madhavan S, Ooi WL, Cohen H, Sealey JE, Laragh JH. Association of the renin-sodium profile with the risk of myocardial infarction in patients with hypertension. N Engl J Med. 1991 Apr 18;324(16):1098-104.

Study ID Numbers:	980029, 98-H-0029
Study First Received:	November 3, 1999
Last Updated:	March 3, 2008
ClinicalTrials.gov Identifier:	NCT00001741
Health Authority:	United States: Federal Government

Keywords provided by National Institutes of Health Clinical Center (CC):

Angiotensin II Receptor
Polymorphism, Genetic
Vascular Tone
Angiotensin II
Losartan

Study placed in the following topic categories:

Losartan
Angiotensin II

Additional relevant MeSH terms:

Angiotensin II Type 1 Receptor Blockers
Molecular Mechanisms of Pharmacological Action
Therapeutic Uses
Vasoconstrictor Agents
Cardiovascular Diseases

Anti-Arrhythmia Agents
Cardiovascular Agents
Antihypertensive Agents
Pharmacologic Actions

ClinicalTrials.gov processed this record on January 15, 2009