Clinical trial NCT00182923: Forearm Vascular Relaxation
Official title: Determinants of Forearm Vascular Relaxation: Role of Genetic Polymorphisms
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Healthy
Keywords: Blood pressure
genetics
Lead sponsor: National Institute on Aging (NIA)
Sponsor class: NIH
First posted: 2005-09-16
Enrollment: 400
Sex: ALL
Minimum age (years): 21
Maximum age (years): 45
Standard ages: ADULT
Accepts healthy volunteers: yes
Time perspective: PROSPECTIVE

Brief summary: The purpose of this study is to learn the effect of inherited differences on forearm blood flow responses to hormones and drugs

Detailed description: Differences in at least 4 genes are believed to have an important effect on responses to hormones and drugs. For this study, healthy volunteers of normal body weight will be screened to find xxx individuals with the genes of interest. Very small doses of hormones and drugs will be given so that changes in forearm blood flow can be measured, while not causing effects throughout the body. A brachial artery line and venous line will be placed in the study arm so that blood samples may be withdrawn to compare amounts given into the artery and coming out of the vein after circulating through the arm. Forearm blood flow is determined by the rate of swelling of the arm after a blood pressure cuff is inflated (above venous and below arterial blood pressure). The hormones and drugs being studied include angiotensin I, angiotensin II, acetylcholine, sodium nitroprusside, enalaprilat, L-arginine, phenylephrine, endothelin-1, verapamil, and isoproterenol. This procedure will last 4-6 hours. The process will be repeated with the same participant over 2 weeks later.

Eligibility criteria: Inclusion Criteria:

* Normal physical status without any medical interventions or agents which would alter the defined status of normal

Exclusion Criteria:

* Age less than 21 or greater than 45
* Unable to give informed consent
* BMI (Body Mass Index) less than 18 or greater than 25
* Clinically significant abnormal laboratory values
* Abnormal physical exam
* Abnormal EKG
* Pregnancy
* Smoking or drug usage (illicit or otherwise)
* Post-menopause
* Participation in another clinical trial in the past month
* Chronic Illness

Primary outcomes:
Secondary outcomes:
Other outcomes:
Locations:
city: Baltimore
country: United States
facility: National Institute on Aging (NIA), Harbor Hospital
state: Maryland
Study officials:
affiliation: National Institute on Aging, Laboratory of Clinical Investigation
name: Darrell R. Abernethy, MD, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Abernethy DR, Laurie N, Andrawis NS. Local angiotensin-converting enzyme inhibition blunts endothelin-1-induced increase in forearm vascular resistance. Clin Pharmacol Ther. 1995 Sep;58(3):328-34. doi: 10.1016/0009-9236(95)90250-3.
citation: Abernethy DR, Winterbottom LM. Forearm vascular alpha 1-adrenergic blockade by verapamil. Clin Pharmacol Ther. 1990 Jun;47(6):755-9. doi: 10.1038/clpt.1990.104.
citation: Andrawis NS, Craft N, Abernethy DR. Calcium antagonists block angiotensin II-mediated vasoconstriction in humans: comparison with their effect on phenylephrine-induced vasoconstriction. J Pharmacol Exp Ther. 1992 Jun;261(3):879-84.