Study of the Response of Human Small Blood Vessels

Phase 1

Completed

• Conditions: Healthy; Hypertension; Hypercholesterolemia

• Registration Number: NCT00001622
• Lead Sponsor: National Heart, Lung, and Blood Institute (NHLBI)

Brief 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. One of the substances produced involved in the control of blood vessel function is nitric oxide. Nitric oxide (NO) plays a role in the relaxation of blood vessels.

Researchers have been interested in the function of the endothelium in patients with high blood pressure (essential hypertension) and patients with high cholesterol (hypercholesterolemia).

After conducting studies on the endothelium and nitric oxide, researchers have found that the endothelium is indeed functioning abnormally in patients with high blood pressure and high cholesterol. In addition, researchers have determined that the dysfunction is a result of abnormalities in the nitric oxide (NO) system.

In this study researchers plan to investigate the relationship between blood vessel responses in real-life settings versus laboratory settings in normal volunteers, patients with high blood pressure, and patients with high cholesterol.

Detailed Description

Over the last ten years, we have been interested in the investigation of endothelial function in patients with essential hypertension and patients with hypercholesterolemia. We have performed intra-arterial infusion of endothelium-dependent and endothelium-independent drugs into the brachial artery with noninvasive measurement of the response of the forearm vasculature by means of strain gauge plethysmography. Those studies have allowed us to: a) demonstrate the presence of endothelial dysfunction in patients with essential hypertension and in patients with hypercholesterolemia; and b) identify an abnormality in the endothelium-derived nitric oxide system that is responsible for endothelial dysfunction in these patients. Further studies to more precisely determine the intracellular processes that mediate this abnormality in endothelial function in these patients are limited by the inherent shortcomings of the in vivo technique. An alternative possibility is the study of human small vessels in vitro; however, the relationship between in vivo and in vitro vascular responses to endothelium-dependent and -independent agonists has not been established. In the present study, we propose to investigate this relationship in normal volunteers, patients with essential hypertension, and patients with hypercholesterolemia.

Study Timeline

• Study Start: 1997-03
• Study First Submitted: 1999-11-03
• Status Verified: 2000-01
• Study Completion: 2001-03
• Study First Submitted QC: 2002-12-09
• Study First Posted: 2002-12-10
• Last Update Submitted: 2008-03-03
• Last Update Posted: 2008-03-04

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 87

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: Not specified

Trial Locations

Locations (1)

National Heart, Lung and Blood Institute (NHLBI); 🇺🇸 Bethesda, Maryland, United States