Featured Research

from universities, journals, and other organizations

Scientists discover new mechanisms for relaxing airways using bitter tasting substances

Date:
March 5, 2013
Source:
University of Massachusetts Medical School
Summary:
An interdisciplinary team of scientists have taken a step forward in understanding how the substances that give some foods their bitter flavor also act to reverse the contraction of airway cells, a process known as bronchodilation. This effect may one day be harnessed to provide improved treatments for airway obstructive diseases such as asthma and chronic obstructive pulmonary disease.

That kale and bitter melon you are eating may someday save your life. An interdisciplinary team of scientists at the University of Massachusetts Medical School have taken a step forward in understanding how the substances that give some foods their bitter flavor also act to reverse the contraction of airway cells, a process known as bronchodilation. This effect may one day be harnessed to provide improved treatments for airway obstructive diseases such as asthma and chronic obstructive pulmonary disease.

Related Articles


The findings were published on March 5 in the open access journal PLOS Biology.

"I am excited that someday, with more research, there may be a new class of bronchodilators which are able to reverse an asthma attack quicker and with fewer side effects than is currently available to patients," said Ronghua ZhuGe, PhD, associate professor of microbiology and physiological systems and senior author of the study.

The sense of taste is mediated by taste receptor cells bundled in our taste buds. Most humans experience five types of tastes: sweet, salty, sour, bitter and savory. Bitter taste receptors most likely evolved to help alert the body to potentially harmful foods that have spoiled or are toxic. The receptors have long been thought to only exist in certain cells present in the tongue. Over the last few years, however, scientists have come to realize that these receptors are present in many other cells throughout the body. Specifically, bitter taste receptors on smooth muscle cells in the airway act to relax the cells when exposed to bitter-tasting substances.

A hallmark of an asthma attack is excessive contraction of smooth muscle cells, which causes narrowing of the airways and subsequent breathing difficulties. The fact that bitter substances can relax these smooth muscle cells suggests that they may have the potential to halt asthma attacks and in fact could even be an improvement over current treatments since the relaxation effects are quite fast. Indeed, experiments in mice suggest that the effects are stronger.

However, the mechanisms by which bitter taste receptor activation causes a cell to relax were unknown. To help unravel these mechanisms, Dr. ZhuGe and colleagues examined the effect of bitter substances on the contraction of airways and in single isolated cells.

During an asthma attack, channels on the membrane of smooth muscle cells in the airways open. This allows calcium to flow into the cell, causing it to contract. When the cells contract, the airway becomes narrower and makes breathing more difficult. Dr. ZhuGe and colleagues determined that bitter substances act by shutting down these calcium channels, allowing bronchodilation.

Bitter taste receptors, like most receptors, span the plasma membrane of the cell. Part of the receptor is outside the cell, able to bind (and hence "sense") bitter substances outside the cell. When a bitter compound binds to a bitter taste receptor, the receptor releases a G-protein, which then splits into two parts: a G alpha subunit and G beta-gamma dimer. "It is the G beta-gamma dimer that likely acts to close the calcium channels on the plasma membrane," said Kevin Fogarty, director of the biomedical imaging group in the program in molecular medicine at UMMS, and a co-author of the study. "Once the channels are closed, the calcium level returns to normal and the cell relaxs," he said. "This ends the asthma attack."

"With this new understanding of how bitter substances are able to relax airways, we can focus our attention on studying these receptors and on finding even more potent bitter compounds with the potential to be used therapeutically to end asthma attacks," said Dr. ZhuGe.


Story Source:

The above story is based on materials provided by University of Massachusetts Medical School. Note: Materials may be edited for content and length.


Journal Reference:

  1. Cheng-Hai Zhang, Lawrence M. Lifshitz, Karl F. Uy, Mitsuo Ikebe, Kevin E. Fogarty, Ronghua ZhuGe. The Cellular and Molecular Basis of Bitter Tastant-Induced Bronchodilation. PLoS Biology, 2013; 11 (3): e1001501 DOI: 10.1371/journal.pbio.1001501

Cite This Page:

University of Massachusetts Medical School. "Scientists discover new mechanisms for relaxing airways using bitter tasting substances." ScienceDaily. ScienceDaily, 5 March 2013. <www.sciencedaily.com/releases/2013/03/130305174528.htm>.
University of Massachusetts Medical School. (2013, March 5). Scientists discover new mechanisms for relaxing airways using bitter tasting substances. ScienceDaily. Retrieved November 28, 2014 from www.sciencedaily.com/releases/2013/03/130305174528.htm
University of Massachusetts Medical School. "Scientists discover new mechanisms for relaxing airways using bitter tasting substances." ScienceDaily. www.sciencedaily.com/releases/2013/03/130305174528.htm (accessed November 28, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Friday, November 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Rural India's Low-Cost Sanitary Pad Revolution

Rural India's Low-Cost Sanitary Pad Revolution

AFP (Nov. 28, 2014) — One man hopes his invention -– a machine that produces cheap sanitary pads –- will help empower Indian women. Duration: 01:51 Video provided by AFP
Powered by NewsLook.com
Research on Bats Could Help Develop Drugs Against Ebola

Research on Bats Could Help Develop Drugs Against Ebola

AFP (Nov. 28, 2014) — In Africa's only biosafety level 4 laboratory, scientists have been carrying out experiments on bats to understand how virus like Ebola are being transmitted, and how some of them resist to it. Duration: 01:18 Video provided by AFP
Powered by NewsLook.com
Ebola Leaves Orphans Alone in Sierra Leone

Ebola Leaves Orphans Alone in Sierra Leone

AFP (Nov. 27, 2014) — The Ebola epidemic sweeping Sierra Leone is having a profound effect on the country's children, many of whom have been left without any family members to support them. Duration: 01:02 Video provided by AFP
Powered by NewsLook.com
Experimental Ebola Vaccine Shows Promise In Human Trial

Experimental Ebola Vaccine Shows Promise In Human Trial

Newsy (Nov. 27, 2014) — A recent test of a prototype Ebola vaccine generated an immune response to the disease in subjects. 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