Featured Research

from universities, journals, and other organizations

A new drug for heat stroke? Implications for malignant hyperthermia

Date:
January 12, 2012
Source:
Malignant Hyperthermia Association of the United States
Summary:
Malignant hyperthermia (MH) is a life-threatening genetic muscle disorder, most commonly triggered in those at risk by certain types of drugs used during anesthesia. Heat stroke, on the other hand, most commonly occurs in individuals in response to physical exertion in hot/humid environments. While their common triggers may differ, the signs associated with MH and heat stroke are remarkably similar – uncontrolled muscle contractions, dangerous increases in body temperature, and muscle breakdown leading to the release of toxins in the blood which may cause cardiac arrhythmias and death. A new medication may be effective in preventing certain forms of heat stroke.

Malignant hyperthermia (MH) is a life-threatening genetic muscle disorder, most commonly triggered in those at risk by certain types of drugs used during anesthesia. Heat stroke, on the other hand, most commonly occurs in individuals in response to physical exertion in hot/humid environments. While their common triggers may differ, the signs associated with MH and heat stroke are remarkably similar -- uncontrolled muscle contractions, dangerous increases in body temperature, and muscle breakdown leading to the release of toxins in the blood which may cause cardiac arrhythmias and death. Immediate treatment for these conditions is crucial.

Treatments for MH and Heat Stroke The treatment for anesthesia-induced MH is a drug called dantrolene. For heat stroke, options are limited to symptomatic treatment, such as vigorous cooling and hydration. Now, researchers at Baylor College of Medicine (Houston, TX), the University of Rochester (Rochester, NY), and the Joslin Diabetes Center (Boston, MA) have shown that a compound called AICAR, previously shown to slow muscle fatigue and increase muscle endurance, is effective in preventing heat stroke in an animal model of the disorder. This animal model is the same one utilized for MH, though the drug did not protect the mice from anesthetic-induced MH.

A Genetic Link Not only are the signs of MH and heat stroke similar, but there is also a genetic link. Recent studies have shown that genetically engineered 'MH mice' not only develop MH on exposure to anesthesia but also develop an MH-like response similar to heat stroke on exposure to high temperatures. These 'MH mice' harbor a mutation in the ryanodine receptor gene (RYR1) which codes for an important protein, the ryanodine receptor, which controls the level of calcium in the muscle cell. Mutations in RYR1 have also been identified in some humans who suffered from heat stroke.

What were the key findings of this study? In these mice, AICAR prevented increased calcium leak in the muscle cell through the ryanodine receptor during heat challenge, thereby blocking the initiation of abnormal muscle contractions, an initial step in the heat stroke response. AICAR was 100% effective in preventing heat-induced sudden death, or heat stroke in these mice.

Why is this study important? Each year many individuals die or suffer consequences of heat stroke. Heat stroke is not uncommon in the military as well as in athletic competitions. This would be the first demonstration that a medication can be effective in preventing certain forms of heat stroke.

What are the implications of this study for MH-susceptible (MHS) individuals? As we have previously reported, individuals who harbor certain RYR1 mutations may not only be susceptible to anesthetic-induced MH events, but may also be heat sensitive. "In these individuals, AICAR might serve an important protective role against heat stress," notes Susan Hamilton, Ph.D., lead investigator for the study (Baylor College of Medicine).

According to Dr. Henry Rosenberg, President of MHAUS, this study emphasizes the connection between anesthesia-induced MH and environmental heat stroke, and enhances our understanding of the connection between ryanodine receptor genes and many other disorders. It also opens up the possibility for development of other compounds that might be useful in the treatment of MH and other drug-induced disorders characterized by muscle abnormality and elevated body temperature.


Story Source:

The above story is based on materials provided by Malignant Hyperthermia Association of the United States. Note: Materials may be edited for content and length.


Cite This Page:

Malignant Hyperthermia Association of the United States. "A new drug for heat stroke? Implications for malignant hyperthermia." ScienceDaily. ScienceDaily, 12 January 2012. <www.sciencedaily.com/releases/2012/01/120112162417.htm>.
Malignant Hyperthermia Association of the United States. (2012, January 12). A new drug for heat stroke? Implications for malignant hyperthermia. ScienceDaily. Retrieved October 20, 2014 from www.sciencedaily.com/releases/2012/01/120112162417.htm
Malignant Hyperthermia Association of the United States. "A new drug for heat stroke? Implications for malignant hyperthermia." ScienceDaily. www.sciencedaily.com/releases/2012/01/120112162417.htm (accessed October 20, 2014).

Share This



More Mind & Brain News

Monday, October 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Court Ruling Means Kids' Online Activity Could Be On Parents

Court Ruling Means Kids' Online Activity Could Be On Parents

Newsy (Oct. 17, 2014) In a ruling attorneys for both sides agreed was a first of its kind, a Georgia appeals court said parents can be held liable for what kids put online. Video provided by Newsy
Powered by NewsLook.com
The Best Foods To Boost Your Mood

The Best Foods To Boost Your Mood

Buzz60 (Oct. 17, 2014) Feeling down? Reach for the refrigerator, not the medicine cabinet! TC Newman (@PurpleTCNewman) shares some of the best foods to boost your mood. Video provided by Buzz60
Powered by NewsLook.com
You Can Get Addicted To Google Glass, Apparently

You Can Get Addicted To Google Glass, Apparently

Newsy (Oct. 15, 2014) Researchers claim they’ve diagnosed the first example of the disorder in a 31-year-old U.S. Navy serviceman. Video provided by Newsy
Powered by NewsLook.com
First Confirmed Case Of Google Glass Addiction

First Confirmed Case Of Google Glass Addiction

Buzz60 (Oct. 15, 2014) A Google Glass user was treated for Internet Addiction Disorder caused from overuse of the device. Morgan Manousos (@MorganManousos) has the details on how many hours he spent wearing the glasses, and what his symptoms were. Video provided by Buzz60
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