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

Blood Pressure Clinical Trial

Official title:

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

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00240058
• Other study ID #: DRDA05-0222
• Secondary ID: R33DK071222
• Status: Completed
• Phase: N/A
• First received: October 13, 2005
• Last updated: June 1, 2017
• Start date: July 2005
• Est. completion date: June 2006

Study information

• Verified date: June 2017
• Source: University of Michigan
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 22
• Est. completion date: June 2006
• Est. primary completion date: June 2006
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 55 Years

Eligibility

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

Related Conditions & MeSH terms

• Blood Pressure

Intervention

Drug:
• Regional phenylephrine arterial infusion, Nitric Oxide Clamp

Locations

Country	Name	City	State
United States	University of Michigan Hospital	Ann Arbor	Michigan

Sponsors (4)

Lead Sponsor	Collaborator
Crystal A. Gadegbeku	National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH), University of Michigan

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Determine whether alpha 1-adrenoceptor vasoreactivity is reproducible
Primary	Determine alpha 1-adrenoceptor vasoreactivity with the NO clamp technique