Hide glossary Glossary Study record managers: refer to the Data Element Definitions if submitting registration or results information. Search for terms. Save this study. Warning You have reached the maximum number of saved studies Effects of Nitrite on Blood Vessel Dilation in Normal Volunteers The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U. Federal Government.
Read our disclaimer for details. Last Update Posted : March 4, Study Description. Participants will undergo the procedures described in study Parts A and B, as follows: Part A - After numbing the skin, small tubes are placed in the artery and vein at the inside of the elbow of the dominant arm right- or left-handed and a small tube is placed in a vein of the other arm.
The tubes are used for infusing saline salt water and for drawing blood samples. A pressure cuff is placed around the upper part of the dominant arm, and a rubber band device called a strain gauge is also placed around the arm to measure blood flow.
When the cuff is inflated, blood flows into the arm, stretching the strain gauge at a rate proportional to the flow. Grip-strength of the dominant arm is measured with a dynamometer to determine maximum grip-strength. Then, several measurements of blood flow, nitrite, hemoglobin, and handgrip are made before and after administration of L-NMMA, a drug that blocks endothelial production of nitric oxide.
Part B - Part A testing is repeated, except that sodium nitrite dissolved in a saline solution is infused into the artery of the forearm for a few minutes before and during the hand-grip exercises. In addition, blood samples are drawn before and after each handgrip exercise to measure methemoglobin, a substance that, at excessive levels, can cause adverse side effects.
Detailed Description:. Nitric oxide NO is a soluble gas continuously synthesized by the endothelium and contributes importantly to vasodilator tone of the coronary and systemic circulations by activating guanylyl cyclase in vascular smooth muscle, causing relaxation. Although regional synthesis of NO by the endothelium contributes to local vasodilator tone, we have shown previously that NO may be transported in blood, and have biological effects at a distance from the site of entry into the circulation.
Thus, we found that NO may be transported bound to heme iron in red blood cells and released at vascular sites of deficient NO synthesis, restoring vasodilator tone. For people with chronic inflammatory conditions, vasoconstrictors reduce inflammation by restricting blood flow to certain cells and body tissues. Vasodilation refers to the widening, or dilation, of the blood vessels.
It is a natural process that increases blood flow and provides extra oxygen to the tissues that need it most. In some cases, doctors may deliberately induce vasodilation as a treatment for certain health conditions. In other cases, doctors may work to reduce vasodilation, as it can worsen conditions such as hypotension and chronic inflammatory diseases.
Doctors sometimes use drugs called vasoconstrictors to help treat these conditions. Learn about healthy blood pressure ranges and when to see a doctor in this…. Women can experience health problems and complications during pregnancy, and one such condition is eclampsia. Anxiety may cause high blood pressure, and high blood pressure may also cause anxiety. Read about the link between these conditions and the treatment….
Broken blood vessels or spider veins are enlarged blood vessels under the skin. They can occur anywhere but can appear on the face for a variety of…. High blood pressure is known as the silent killer as it rarely has symptoms. Read this article to learn how to diagnose it and when to seek help.
What to know about vasodilation. Medically reviewed by Deborah Weatherspoon, Ph. Function Causes Vasoconstriction Associated conditions What affects it?
Share on Pinterest Vasodilation may occur when a person exercises. Vasodilation vs. Conditions associated with vasodilation. Factors that can affect vasodilation. Medications that induce or treat vasodilation. Exposure to air pollutants may amplify risk for depression in healthy individuals. Costs associated with obesity may account for 3. Related Coverage. Blood pressure chart: Ranges and guide.
Medically reviewed by Dr. Payal Kohli, M. Everything you need to know about eclampsia. Medically reviewed by Alana Biggers, M. What is the link between anxiety and high blood pressure? What causes broken blood vessels on the face?
Dinenno said the Mayo Clinic is an important partner because it has one of the only hyperbaric chambers in the world that supports invasive studies in humans. The Mayo Clinic also sees a significant number of cystic fibrosis patients who, along with older adults, will be key test subjects because their ATP levels remain unchanged during exercise, while the levels of the chemical can double in young, healthy individuals, who are also part of the study.
In this next step, Dinenno says, he and Joyner are hoping to support the theory that ATP is indeed an important chemical that signals the vessels to expand when and where more oxygen is needed. They expect to demonstrate that as more oxygen is introduced into the blood, there is less ATP released by red blood cells, and when oxygen is lowered, ATP release is increased. In the cystic fibrosis patients and older adults, there are several possible outcomes when oxygen levels in the blood are manipulated.
First, their bodies could respond normally, with ATP and blood flow both increasing at lowered oxygen levels, which Dinenno said is unlikely given pilot data generated for the proposal.
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