Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Discovery of taste receptors in the lungs could help people with asthma breathe easier

25.10.2010
University of Maryland School of Maryland researchers show bitter compounds open lung airways better than current drugs

Taste receptors in the lungs? Researchers at the University of Maryland School of Medicine in Baltimore have discovered that bitter taste receptors are not just located in the mouth but also in human lungs. What they learned about the role of the receptors could revolutionize the treatment of asthma and other obstructive lung diseases.

"The detection of functioning taste receptors on smooth muscle of the bronchus in the lungs was so unexpected that we were at first quite skeptical ourselves," says the study's senior author, Stephen B. Liggett, M.D., professor of medicine and physiology at the University of Maryland School of Medicine and director of its Cardiopulmonary Genomics Program.

Dr. Liggett, a pulmonologist, says his team found the taste receptors by accident, during an earlier, unrelated study of human lung muscle receptors that regulate airway contraction and relaxation. The airways are the pathways that move air in and out of the lungs, one of several critical steps in the process of delivering oxygen to cells throughout the body. In asthma, the smooth muscle airways contract or tighten, impeding the flow of air, causing wheezing and shortness of breath.

The taste receptors in the lungs are the same as those on the tongue. The tongue's receptors are clustered in taste buds, which send signals to the brain. The researchers say that in the lung, the taste receptors are not clustered in buds and do not send signals to the brain, yet they respond to substances that have a bitter taste.

For the current study, Dr. Liggett's team exposed bitter-tasting compounds to human and mouse airways, individual airway smooth muscle cells, and to mice with asthma. The findings are published online in Nature Medicine.

Most plant-based poisons are bitter, so the researchers thought the purpose of the lung's taste receptors was similar to those in the tongue – to warn against poisons. "I initially thought the bitter-taste receptors in the lungs would prompt a 'fight or flight' response to a noxious inhalant, causing chest tightness and coughing so you would leave the toxic environment, but that's not what we found," says Dr. Liggett.

There are thousands of compounds that activate the body's bitter taste receptors but are not toxic in appropriate doses. Many are synthetic agents, developed for different purposes, and others come from natural origins, such as certain vegetables, flowers, berries and trees.

The researchers tested a few standard bitter substances known to activate these receptors. "It turns out that the bitter compounds worked the opposite way from what we thought," says Dr. Liggett. "They all opened the airway more profoundly than any known drug that we have for treatment of asthma or chronic obstructive pulmonary disease (COPD)." Dr. Liggett says this observation could have implications for new therapies. "New drugs to treat asthma, emphysema or chronic bronchitis are needed," he says. "This could replace or enhance what is now in use, and represents a completely new approach."

Quinine and chloroquine have been used to treat completely different diseases (such as malaria), but are also very bitter. Both of these compounds opened contracted airways profoundly in laboratory models. Even saccharin, which has a bitter aftertaste, was effective at stimulating these receptors. The researchers also found that administration of an aerosolized form of bitter substances relaxed the airways in a mouse model of asthma, showing that they could potentially be an effective treatment for this disease.

Dr. Liggett cautions that eating bitter tasting foods or compounds would not help in the treatment of asthma. "Based on our research, we think that the best drugs would be chemical modifications of bitter compounds, which would be aerosolized and then inhaled into the lungs with an inhaler," he says.

Another paradoxical aspect of their discovery is the unexpected role that the mineral calcium plays when the lung's taste receptors are activated. The study's principal author, Deepak A. Deshpande, Ph.D., assistant professor of medicine at the University of Maryland School of Medicine, is an expert in how calcium controls muscles. "We always assumed that increased calcium in the smooth muscle cell caused it to contract, but we found that bitter compounds increase calcium and cause relaxation of airway muscle in a unique way," says Dr. Deshpande. "It appears that these taste receptors are wired to a special pool of calcium that is right at the edge of these cells," he says.

"The work of this team exemplifies what it takes to make real improvements in treating certain diseases," says E. Albert Reece, M.D., Ph.D., M.B.A., vice president for medical affairs at the University of Maryland and dean of the University of Maryland School of Medicine. "These researchers were willing to take chances and ask questions about an unlikely concept. Why are taste receptors in the lungs? What do they do? Can we take advantage of them to devise a new therapy? In the end, their discoveries are in the best tradition of scientific research."

Asthma and COPD together affect 300 million people worldwide. According to the American Lung Association, asthma affects nearly 23 million Americans, including seven million children, and COPD is the fourth leading cause of death in the United States. The incidence of both diseases is increasing. At least half of all asthma patients have inadequate control of the disease using drugs currently available.

Two investigators from Johns Hopkins University, Steven S. An and James S. K. Sham, also contributed to some of the experiments.

This research was supported by grants from the National Heart, Lung, and Blood Institute of the National Institutes of Health.

Deshpande DA, Wang WCH, McIlmoyle EL, Robinett KS, Schillinger RM, An SS, Sham JSK, Liggett SB. "Bitter taste receptors on airway smooth muscle bronchodilate by localized calcium signaling and reverse obstruction." Nature Medicine. Published online October 24, 2010.

Sharon Boston | EurekAlert!
Further information:
http://www.umm.edu

Further reports about: COPD Discovery Nature Immunology smooth muscle

More articles from Health and Medicine:

nachricht Penn study identifies new malaria parasites in wild bonobos
21.11.2017 | University of Pennsylvania School of Medicine

nachricht NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures
17.11.2017 | National Institute of Standards and Technology (NIST)

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Previous evidence of water on mars now identified as grainflows

21.11.2017 | Physics and Astronomy

NASA's James Webb Space Telescope completes final cryogenic testing

21.11.2017 | Physics and Astronomy

New catalyst controls activation of a carbon-hydrogen bond

21.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>