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Protocol Number:
07-H-0124
- Title:
Pilot Study for the Development of Transient Forearm Endothelial Dysfunction
- Number:
07-H-0124
- Summary:
This study will develop a model system that can be used to test medications for improving the ability of blood vessels to resist damage from diseases such as heart attack and stroke. The endothelium (inner layer of blood vessels) has built-in defense mechanisms to prevent blockage of blood flow, including the ability to stretch the vessel when it senses that blood flow is threatened. People with heart attack risk factors, such as high cholesterol, smoking and diabetes lose this ability. This study will develop a model that can measure the response to a lack of blood flow in the arm and be used to test new medicines to improve blood vessel health.
Healthy males between 18 and 45 years of age who have no history of high blood pressure, high cholesterol, or diabetes and who have not smoked for at least 3 months before entering the study may be eligible to enroll.
Participants lie in an adjustable reclining bed. Small catheters (tubes) are placed in the artery and vein of the forearm of the non-dominant arm at the inside of the elbow. Blood samples are collected from the tubes. Then, pressure cuffs are placed on both wrists and upper arms. A strain gauge (rubber band-type device) is placed around the forearms. The pressure cuffs are inflated and blood flows into the forearm, stretching the strain gauge at a rate proportional to the blood flow. Then, small doses of acetylcholine (a medicine that causes blood vessels to expand) are injected into the artery tube. After 20 minutes, blood flow to the non-dominant arm is blocked by inflating the pressure cuff. The subject squeezes a rubber ball about every 2 seconds for 90 seconds. The cuff is deflated after 15 minutes and blood samples are withdrawn from the tube in the vein. After 15 minutes, the procedure is repeated one more time.
- Sponsoring Institute:
-
National Heart, Lung and Blood Institute (NHLBI)
- Recruitment Detail
- Type:
Clinical hold/Recruitment or enrollment suspended
- Gender:
Male
- Referral Letter Required:
No
- Population Exclusion(s):
Female
Children
- Eligibility Criteria:
This study is not currently recruiting new subjects. If you have questions about participating in a study, please contact the Patient Recruitment and Public Liaison Office, CC.
- Special Instructions:
Currently Not Provided
- Keyword(s):
-
Forearm Ischemia
-
Endothelial Function
-
Acetyicholine Vasodilation
-
Venous Plethysmography
- Recruitment Keyword(s):
-
Healthy Volunteer
-
HV
- Condition(s):
-
Limb Ischemia
-
Ischemic Preconditioning
- Investigational Drug(s):
-
Acetylcholine
- Investigational Device(s):
- None
- Interventions:
-
Procedure/Surgery: Limb Ischemia
-
Drug: Acetylcholine
- Supporting Site:
-
National Heart, Lung and Blood Institute
- Contact(s):
-
This study is not currently recruiting new subjects. If you have questions about participating in a study, please contact the Patient Recruitment and Public Liaison Office, CC.
- Citation(s):
-
Rongen GA, Oyen WJ, Ramakers BP, Riksen NP, Boerman OC, Steinmetz N, Smits P. Annexin A5 scintigraphy of forearm as a novel in vivo model of skeletal muscle preconditioning in humans. Circulation. 2005 Jan 18;111(2):120-1. Circulation. 2005 Jan 18;111(2):173-8. Epub 2004 Dec 27
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Kharbanda RK, Peters M, Walton B, Kattenhorn M, Mullen M, Klein N, Vallance P, Deanfield J, MacAllister R. Ischemic preconditioning prevents endothelial injury and systemic neutrophil activation during ischemia-reperfusion in humans in vivo. Circulation. 2001 Mar 27;103(12):1624-30
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Broadhead MW, Kharbanda RK, Peters MJ, MacAllister RJ. KATP channel activation induces ischemic preconditioning of the endothelium in humans in vivo. Circulation. 2004 Oct 12;110(15):2077-82. Epub 2004 Oct 4
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