Expired Study
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Bethesda, Maryland 20892


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.


Study summary:

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.


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.


Study is Available At:


Original ID:

980029


NCT ID:

NCT00001741


Secondary ID:

98-H-0029


Study Acronym:


Brief Title:

Study of Inherited Changes of Receptors Located on Blood Vessels


Official Title:

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


Overall Status:

Completed


Study Phase:

Phase 1


Genders:

Both


Minimum Age:

N/A


Maximum Age:

N/A


Quick Facts

Healthy Volunteers
Oversight Has DMC
Study Is FDA Regulated
Study Is Section 801
Has Expanded Access

Study Source:

National Institutes of Health Clinical Center (CC)


Oversight Authority:

United States: Federal Government


Reasons Why Stopped:


Study Type:

Interventional


Study Design:

Endpoint Classification: Safety Study, Primary Pu


Number of Arms:

0


Number of Groups:

0


Total Enrollment:

200


Enrollment Type:


Study Dates

Start Date:November 1997
Completion Date:April 2003
Verification Date:April 2003
Last Changed Date:March 3, 2008
First Received Date:November 3, 1999

Study Outcomes

There are no available Study Outcomes

Study Interventions

Intervention Type:Drug
Name:Losartan

Study Arms

There are no available Study Arms

Study Agencies

Agency Class:NIH
Agency Type:Lead Sponsor
Agency Name:National Heart, Lung, and Blood Institute (NHLBI)

Sample and Retention Information

There are no available Sample and Retention Information

Study References

Reference Type:Reference
Citation: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.
PMID:1759997
Reference Type:Reference
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.
PMID:1328889
Reference Type:Reference
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.
PMID:1976655

Data Source: ClinicalTrials.gov

Date Processed: January 21, 2020

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