Study of Inherited Changes of Receptors Located on Blood Vessels

Cardiovascular Disease Clinical Trial

Official title:

Study of Vascular Responsiveness in Subjects With Polymorphisms of the Angiotensin II Type I Receptor Gene

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00001741
• Other study ID #: 980029
• Secondary ID: 98-H-0029
• Status: Completed
• Phase: Phase 1
• First received: November 3, 1999
• Last updated: March 3, 2008
• Start date: November 1997
• Est. completion date: April 2003

Study information

• Verified date: April 2003
• Source: National Institutes of Health Clinical Center (CC)
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Federal Government
• Study type: Interventional

Clinical Trial Summary

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.

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 200
• Est. completion date: April 2003
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Both
• Age group: N/A and older

Eligibility

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.

Study Design

Endpoint Classification: Safety Study, Primary Purpose: Treatment

Related Conditions & MeSH terms

• Cardiovascular Disease
• Cardiovascular Diseases

Intervention

Drug:
• Losartan

Locations

Country	Name	City	State
United States	National Heart, Lung and Blood Institute (NHLBI)	Bethesda	Maryland

Sponsors (1)

Lead Sponsor	Collaborator
National Heart, Lung, and Blood Institute (NHLBI)

Country where clinical trial is conducted

United States, 

References & Publications (3)

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. — View Citation

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. — View Citation

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. — View Citation