Study of Inherited Changes of Receptors Located on Blood Vessels

This study has been completed.

Sponsor:

Information provided by:

National Institutes of Health Clinical Center (CC)

ClinicalTrials.gov Identifier:

NCT00001741

First received: November 3, 1999

Last updated: March 3, 2008

Last verified: April 2003

History of Changes

Tracking Information
First Received Date ^ICMJE	November 3, 1999
Last Updated Date	March 3, 2008
Start Date ^ICMJE	November 1997
Primary Completion Date	Not Provided
Current Primary Outcome Measures ^ICMJE	Not Provided
Original Primary Outcome Measures ^ICMJE	Not Provided
Change History	Complete list of historical versions of study NCT00001741 on ClinicalTrials.gov Archive Site
Current Secondary Outcome Measures ^ICMJE	Not Provided
Original Secondary Outcome Measures ^ICMJE	Not Provided
Current Other Outcome Measures ^ICMJE	Not Provided
Original Other Outcome Measures ^ICMJE	Not Provided

Descriptive Information
Brief Title ^ICMJE	Study of Inherited Changes of Receptors Located on Blood Vessels
Official Title ^ICMJE	Study of Vascular Responsiveness in Subjects With Polymorphisms of the Angiotensin II Type I Receptor Gene
Brief 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.
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.
Study Type ^ICMJE	Interventional
Study Phase	Phase 1
Study Design ^ICMJE	Endpoint Classification: Safety Study Primary Purpose: Treatment
Condition ^ICMJE	Cardiovascular Disease
Intervention ^ICMJE	Drug: Losartan
Study Arm (s)	Not Provided
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.
* Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.

Recruitment Information
Recruitment Status ^ICMJE	Completed
Enrollment ^ICMJE	200
Completion Date	April 2003
Primary Completion Date	Not Provided
Eligibility Criteria ^ICMJE	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.
Gender	Both
Ages	Not Provided
Accepts Healthy Volunteers	Yes
Contacts ^ICMJE	Contact information is only displayed when the study is recruiting subjects
Location Countries ^ICMJE	United States

Administrative Information
NCT Number ^ICMJE	NCT00001741
Other Study ID Numbers ^ICMJE	980029, 98-H-0029
Has Data Monitoring Committee	Not Provided
Responsible Party	Not Provided
Study Sponsor ^ICMJE	National Heart, Lung, and Blood Institute (NHLBI)
Collaborators ^ICMJE	Not Provided
Investigators ^ICMJE	Not Provided
Information Provided By	National Institutes of Health Clinical Center (CC)
Verification Date	April 2003
^ICMJE Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP

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