Effect of Nitric Oxide Donor on Endothelial Progenitor Cells in Patients With Coronary Artery Disease

Study Summary

Regular exercise reduces the risk of heart problems, in part because it improves the work of the endothelium (the cells that line blood vessels). Exercise appears to release precursor cells from the bone marrow that will later become endothelial cells. A molecule called nitric oxide (NO) appears to be involved in this release. However, some heart patients do not improve their endothelial function despite regular exercise. The researchers believe that the heart disease in these patients may interfere with the normal relationship between exercise and endothelial function. This study is designed to test whether giving a patient nitroglycerin (which is converted to NO in the bloodstream) will increase the release of endothelial precursor cells from the bone marrow. If the study succeeds, it may lead to improved healing of arteries in heart disease patients. Adults may be eligible for this study if they have coronary artery disease and do not take nitroglycerin or nitroglycerin-like medication on a daily basis. Volunteers will be admitted to the Clinical Center on 2 separate nights at least 1 week apart. On the morning after each admission, volunteers will have blood drawn from an arm vein for laboratory tests, and then walk on a treadmill until fatigue or discomfort prevents further exercise, or until asked to stop. On one of their admissions, volunteers will receive 1 tablet of nitroglycerin under the tongue shortly before the treadmill test. Volunteers will be monitored by EKGs and blood pressure tests during the treadmill tests, and will have more blood drawn at about 15 minutes and 24 hours after each treadmill test. Researchers will examine the levels of endothelial precursor cells and nitric oxide in the blood samples taken before and after exercise.

Interventions

• DRUG nitroglycerin