Featured Research

from universities, journals, and other organizations

Spiraling High Blood Pressure Linked To Nitric Oxide Deficiency

Date:
September 6, 2001
Source:
University Of California, Irvine
Summary:
When high blood pressure isn't controlled, it doesn't stay at one high level. Instead, it spirals higher and higher, greatly increasing the risk of heart attack and stroke. According to a UC Irvine College of Medicine study, this pattern occurs because high blood pressure causes the inactivation of nitric oxide, an important molecular regulator of blood pressure. This inactivation then triggers a vicious circle of increased nitric oxide inactivation and ever higher, uncontrolled blood pressure.

Irvine, Calif. - When high blood pressure isn't controlled, it doesn't stay at one high level. Instead, it spirals higher and higher, greatly increasing the risk of heart attack and stroke.

Related Articles


According to a UC Irvine College of Medicine study, this pattern occurs because high blood pressure causes the inactivation of nitric oxide, an important molecular regulator of blood pressure. This inactivation then triggers a vicious circle of increased nitric oxide inactivation and ever higher, uncontrolled blood pressure.

The study is believed to be the first to show how this inactivation can lead to spiraling blood pressure and may lead scientists to develop more effective ways to control high blood pressure. It appears in the September 2001 issue of Kidney International.

The study, conducted on rats by Dr. Nick Vaziri, professor of medicine and chief of nephrology, and his colleagues, found that nitric oxide, which helps control blood pressure by dilating blood vessels, is inactivated by increasing blood pressure. As pressure increases, molecules called free radicals and reactive oxygen species cause cellular damage and inactivate nitric oxide, causing blood pressure to keep rising. As blood pressure continues to rise, more nitric oxide is inactivated, causing pressure to rise even higher.

"This vicious circle of high blood pressure, nitric oxide inactivation and subsequently higher pressure shows us that a rise in blood pressure alone can increase free radicals, which inactivate nitric oxide and raise blood pressure further," Vaziri said. "While the initial causes of high blood pressure are diverse and in many cases unclear, this study shows the importance of making sure high blood pressure is always controlled and may provide greater understanding of how to better do so."

High blood pressure affects more than 25 million Americans and is a major risk factor for heart disease and stroke. The American Heart Association estimates that less than one-third of people with high blood pressure control it effectively.

Vaziri and his colleagues showed previously that increased free radical activity plays an important role in all cases of high blood pressure. They further showed that increased levels of free radicals by themselves can cause hypertension. Harmful levels of free radicals are often reduced by certain antioxidants, including Vitamin E and other chemicals found in food.

In this study, the researchers asked whether hypertension itself can increase this free radical production, using rats that had high blood pressure in the front half of the body and normal pressure in the rear half.

The rats' front halves showed significant increases in a chemical called nitrotyrosine, a product of nitric oxide inactivation by reactive oxygen species. In the rats' rear halves (which had normal blood pressure), no significant increases of this chemical were found, indicating normal levels of free radicals. The researchers concluded that pressure was regulating the amount of free radicals in the body, which inactivated nitric oxide and created the cycle of pressure, leading to cardiovascular and kidney diseases.

"Nitric oxide inactivation was seen in restricted arteries with high pressure but not in open arteries. This indicates that this circle of inactivation and pressure is made worse by the mechanical pressure and not by genetic or hormonal interactions affecting the body as a whole," Vaziri said. "Free radicals and other such molecules, then, play a much stronger role in high blood pressure than has been previously assumed. These molecules may hold the key to controlling excessively high pressure and perhaps to better treatments using antioxidants and other chemicals to keep pressure normal."

Vaziri and his colleagues have been focusing for years on the complex chemical interactions that lead to high blood pressure. They now are working on a number of experiments to better define the relationships between blood pressure, nitric oxide and the risk of disease in the kidney, heart and brain.

Vaziri's colleagues in the study include Drs. Cyril Barton and Zhemin Ni of UCI.


Story Source:

The above story is based on materials provided by University Of California, Irvine. Note: Materials may be edited for content and length.


Cite This Page:

University Of California, Irvine. "Spiraling High Blood Pressure Linked To Nitric Oxide Deficiency." ScienceDaily. ScienceDaily, 6 September 2001. <www.sciencedaily.com/releases/2001/09/010905074425.htm>.
University Of California, Irvine. (2001, September 6). Spiraling High Blood Pressure Linked To Nitric Oxide Deficiency. ScienceDaily. Retrieved December 22, 2014 from www.sciencedaily.com/releases/2001/09/010905074425.htm
University Of California, Irvine. "Spiraling High Blood Pressure Linked To Nitric Oxide Deficiency." ScienceDaily. www.sciencedaily.com/releases/2001/09/010905074425.htm (accessed December 22, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Monday, December 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Touch-Free Smart Phone Empowers Mobility-Impaired

Touch-Free Smart Phone Empowers Mobility-Impaired

Reuters - Innovations Video Online (Dec. 21, 2014) A touch-free phone developed in Israel enables the mobility-impaired to operate smart phones with just a movement of the head. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Earthworms Provide Cancer-Fighting Bacteria

Earthworms Provide Cancer-Fighting Bacteria

Reuters - Innovations Video Online (Dec. 21, 2014) Polish scientists isolate bacteria from earthworm intestines which they say may be used in antibiotics and cancer treatments. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Existing Chemical Compounds Could Revive Failing Antibiotics, Says Danish Scientist

Existing Chemical Compounds Could Revive Failing Antibiotics, Says Danish Scientist

Reuters - Innovations Video Online (Dec. 21, 2014) A team of scientists led by Danish chemist Jorn Christensen says they have isolated two chemical compounds within an existing antipsychotic medication that could be used to help a range of failing antibiotics work against killer bacterial infections, such as Tuberculosis. Jim Drury went to meet him. Video provided by Reuters
Powered by NewsLook.com
Hugging It Out Could Help You Ward Off A Cold

Hugging It Out Could Help You Ward Off A Cold

Newsy (Dec. 21, 2014) Carnegie Mellon researchers found frequent hugs can help people avoid stress-related illnesses. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins