Pilot Study On The Role Of Nitric Oxide In Alpha 1-Adrenergic Vasoreactivity

NCT ID: NCT00240058

Last Updated: 2017-06-05

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 22 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2005-07-31
• Study Completion Date: 2006-06-30

Brief Summary

This is a research project to test two study techniques among healthy adults. The procedures look at how blood flow is controlled by substances in blood vessels.

Detailed Description

Most patients with chronic kidney disease (CKD) have high blood pressure and are at high risk for cardiovascular disease. High blood pressure can be partly caused by narrowing of blood vessels from high activity of the alpha1-adrenoceptor system in blood vessels. On the other hand, nitric oxide (NO), produced by the body, opposes the alpha 1-adrenoceptor system. NO widens blood vessels and prevents high blood pressure. We hypothesize that low availability of NO may be responsible for high activity of alpha 1-adrenoceptor system in patients with CKD. This protocol is a pilot study in healthy subjects to guide us in performing future studies in patients with CKD.

The specific aims of the pilot study, in healthy people, are to 1) determine whether alpha 1-adrenoceptor vasoreactivity is reproducible and 2) determine alpha 1-adrenoceptor vasoreactivity with the NO clamp technique. To carry out these specific aims, we will consent and enroll healthy people with normal blood pressure. After a screening visit to confirm eligibility, subjects will be admitted to the General Clinical Research Center overnight for a study the following day.

We will constrict the forearm blood vessels by giving different amounts of phenylephrine into the artery through a catheter. We will measure the subjects blood flow with venus plethysmography ( a measuring tool like a blood pressure cuff) while giving the phenylephrine. We will repeat the tests to see if we get the same results.

Then, a research medication, L-NMMA, which blocks NO in the blood vessel, will be dripped into the same artery followed by another medication nitroprusside, which gives back NO, to restore normal forearm blood flow. This procedure is called the NO clamp technique and is used to measure the effects of NO. The phenylephrine concentrations and plethysmography will be repeated again to compare vessel narrowing before and during the NO clamp. This research will teach us how to perform future studies on the relationship between NO and the alpha 1-adrenoceptor system in patients with kidney disease.

Conditions

Blood Pressure

Study Design

• Allocation Method: NON_RANDOMIZED
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: OTHER
• Blinding Strategy: NONE

Study Groups

phenylephrine infusion with and without nitric oxide clamp

Participants received phenylephrine infusion with saline followed by phenylephrine infusion with nitric oxide clamp

Group Type: OTHER

Regional phenylephrine arterial infusion, Nitric Oxide Clamp

Intervention Type: DRUG

Interventions

Regional phenylephrine arterial infusion, Nitric Oxide Clamp

Intervention Type: DRUG

Eligibility Criteria

Inclusion Criteria

Healthy men and women:

• Age 18 to 55 years
• Who have Blood Pressure less than or equal to 120/80.

Exclusion Criteria

Individuals with:

• Diabetes, lung disease
• Stomach disease, liver disease
• Blood vessel disease
• Kidney disease
• High blood pressure
• Heart disease
• Hereditary blood disorders
• Hematocrit (amount of red blood cells) less than 30%,
• Who smoke
• Women who are pregnant or lactating

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 55 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

National Institutes of Health (NIH)

NIH

Sponsor Role: collaborator

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

NIH

Sponsor Role: collaborator

University of Michigan

OTHER

Sponsor Role: collaborator

Crystal A. Gadegbeku

OTHER

Sponsor Role: lead

Responsible Party

Crystal A. Gadegbeku

Assistant Professor of Medicine

Responsibility Role: SPONSOR_INVESTIGATOR

Principal Investigators

Crystal A Gadegbeku, MD

Role: PRINCIPAL_INVESTIGATOR

Assistant Professor of Medicine, University of Michigan Health System, Department of Internal Medicine, Division of Nephrology

Locations

University of Michigan Hospital

Ann Arbor, Michigan, United States

Countries

United States

Related Links

http://www.med.umich.edu/intmed/nephrology/STAFF/gadegbeku_ca1.htm

Principle Investigator research information

Other Identifiers

R33DK071222

Identifier Type: NIH

Identifier Source: secondary_id

View Link

DRDA05-0222

Identifier Type: -

Identifier Source: org_study_id