Featured Research

from universities, journals, and other organizations

Overproduction Of Glutamate Can Lead To Brain Damage During Heart Surgery

Date:
October 14, 1997
Source:
Johns Hopkins Medical Institutions
Summary:
Cooling the body for heart surgery causes an overproduction of the neurotransmitter glutamate, an excitatory amino acid, and can leave the nervous system vulnerable to damage from the start of the cooling process until up to eight hours after recovery, a Johns Hopkins animal study suggests.

Cooling the body for heart surgery causes an overproduction of the neurotransmitter glutamate, an excitatory amino acid, and can leave the nervous system vulnerable to damage from the start of the cooling process until up to eight hours after recovery, a Johns Hopkins animal study suggests. This contradicts previous theories that brain damage occurred only during the initial recovery period.

Results of the study, supported by the National Institutes of Health and the Nina Braunwald Research Fellowship from the Thoracic Surgery Foundation for Research and Education, will be presented Oct. 14 at the American College of Surgeons' annual meeting in Chicago.

During the cooling process, called hypothermic circulatory arrest (HCA), the body temperature is lowered to reduce the need for oxygen, the heart is stopped and a heart-lung bypass machine takes over circulation in an effort to prevent brain damage. Prolonged HCA, however, may increase the risk of brain damage, leading to problems in learning, memory and involuntary movements.

The researchers measured brain levels of the potentially toxic amino acids glutamate, glycine and citrulline (a marker of nitric oxide) in a group of dogs during closed-chest cardiopulmonary bypass and two hours of HCA. Significant increases in glutamate were observed throughout the cooling process, recovery period and up to eight hours post-recovery. Glutamate overproduction led to increases in glycine and citrulline, which were observed during recovery and two to eight hours post-recovery.

"These findings suggest that pharmacologic strategies to protect the brain from injury and cell death during HCA will require targeting the excitatory amino acid pathway throughout the cooling process," says Charles J. Lowenstein, M.D., assistant professor of medicine at Hopkins and an author of the paper.

The study's other authors were lead author Elaine E. Tseng, M.D.; Malcolm V. Brock, M.D.; Christopher C. Kwon, M.S.; Jorge D. Salazar, M.D.; John R. Doty, M.D.; Michael V. Johnston, M.D.; and William A. Baumgartner, M.D.


Story Source:

The above story is based on materials provided by Johns Hopkins Medical Institutions. Note: Materials may be edited for content and length.


Cite This Page:

Johns Hopkins Medical Institutions. "Overproduction Of Glutamate Can Lead To Brain Damage During Heart Surgery." ScienceDaily. ScienceDaily, 14 October 1997. <www.sciencedaily.com/releases/1997/10/971014133419.htm>.
Johns Hopkins Medical Institutions. (1997, October 14). Overproduction Of Glutamate Can Lead To Brain Damage During Heart Surgery. ScienceDaily. Retrieved September 2, 2014 from www.sciencedaily.com/releases/1997/10/971014133419.htm
Johns Hopkins Medical Institutions. "Overproduction Of Glutamate Can Lead To Brain Damage During Heart Surgery." ScienceDaily. www.sciencedaily.com/releases/1997/10/971014133419.htm (accessed September 2, 2014).

Share This




More Health & Medicine News

Tuesday, September 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Get on Your Bike! London Cycling Popularity Soars Despite Danger

Get on Your Bike! London Cycling Popularity Soars Despite Danger

AFP (Sep. 1, 2014) Wedged between buses, lorries and cars, cycling in London isn't for the faint hearted. Nevertheless the number of people choosing to bike in the British capital has doubled over the past 15 years. Duration: 02:27 Video provided by AFP
Powered by NewsLook.com
Can You Train Your Brain To Eat Healthy?

Can You Train Your Brain To Eat Healthy?

Newsy (Sep. 1, 2014) New research says if you condition yourself to eat healthy foods, eventually you'll crave them instead of junk food. Video provided by Newsy
Powered by NewsLook.com
We've Got Mites Living In Our Faces And So Do You

We've Got Mites Living In Our Faces And So Do You

Newsy (Aug. 30, 2014) A new study suggests 100 percent of adult humans (those over 18 years of age) have Demodex mites living in their faces. Video provided by Newsy
Powered by NewsLook.com
Liberia Continues Fight Against Ebola

Liberia Continues Fight Against Ebola

AFP (Aug. 30, 2014) Authorities in Liberia try to stem the spread of the Ebola epidemic by raising awareness and setting up sanitation units for people to wash their hands. Duration: 00:41 Video provided by AFP
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:
from the past week

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