News / Health

Study: Your Lungs Can Smell

A new study says your lungs can sense odors, but that they do so much differently from your nose. (Via Flickr)
A new study says your lungs can sense odors, but that they do so much differently from your nose. (Via <a href="http://www.flickr.com/photos/liverpoolhls/">Flickr</a>)

Related Articles

US Panel: Some Current, Former Smokers Should Get Annual Lung Scans

Under the Affordable Care Act, insurers will be required to cover the screenings

Study: Tobacco Tax Hike Could Save 200 Million Lives

Tripling tobacco taxes would decrease worldwide consumption by about a third, the study said

Study: Chinese Plant Ingredient Eases Chronic Pain

Compound comes from roots of flowering Corydalis herb which Chinese have used for centuries for its analgesic qualities
VOA News
Your lungs can smell. That’s what new research suggests.

But unlike the odor receptors in your nose, which send a message to the brain, the receptors in your lung cause the airways to constrict when a pungent or caustic odor such as cigarette smoke is sensed.

The new class of cells, called pulmonary neuroendocrine cells, or PNECs, were discovered by scientists at Washington University in St. Louis and the University of Iowa.

“Our body plan is a tube within a tube, so our lungs and our gut are open to the external environment,” said Yehuda Ben-Shahar, an assistant professor of biology and of medicine at Washington University in St. Louis.  “Although they’re inside us, they’re actually part of our external layer. So they constantly suffer environmental insults,” he said, “and it makes sense that we evolved mechanisms to protect ourselves.”

The researchers say the cells might be responsible for the chemical hypersensitivity that characterizes respiratory diseases, such as chronic obstructive pulmonary disease (COPD) and asthma. Patients with these diseases are told to avoid traffic fumes, pungent odors, perfumes and similar irritants, which can trigger airway constriction and breathing difficulties.

The odor receptors on the cells might be a therapeutic target, Ben-Shahar suggests. By blocking them, it might be possible to prevent some attacks, allowing people to cut down on the use of steroids or bronchodilators.

When a mammal inhales, volatile chemicals flow over two patches of specialized tissue high up in the nasal passages. These patches are rich in nerve cells with specialized odorant-binding molecules embedded in their membranes.

If a chemical docks on one of these receptors, the neuron fires, sending impulses along the olfactory nerve to the olfactory bulb in the brain, where the signal is integrated with those from hundreds of other similar cells to conjure the scent of old leather or dried lavender.

Aware that airway diseases are characterized by hypersensitivity to volatile stimuli, Ben-Shahar and his colleagues realized that the lungs, like the nose, must have some means of detecting inhaled chemicals.

In 2009, Ben-Shahar found that ciliated cells, cells with tiny hairlike protuberances that are responsible for moving things in the airway, responding to bitterness.

But since people are sensitive to many inhaled substances, not just bitter ones, he wanted to revisit the issue. This time, he found that these tissues also express odor receptors, not on ciliated cells but instead on neuroendocrine cells, flask-shaped cells that dump serotonin and various neuropeptides when they are stimulated.

“When people with airway disease have pathological responses to odors, they’re usually pretty fast and violent,” said Ben-Shahar. “Patients suddenly shut down and can’t breathe, and these cells may explain why.”

Ben-Shahar stresses the differences between chemosensation in the nose and in the lung. The cells in the nose are neurons, he points out, each with a narrowly tuned receptor, and their signals must be woven together in the brain to interpret our odor environment.

Cells in the airways are secretory, not neuronal, cells, and they may carry more than one receptor, so they are broadly tuned. Instead of sending nerve impulses to the brain, they flood local nerves and muscles with serotonin and neuropeptides. “They are possibly designed,” he said, “to elicit a rapid, physiological response if you inhale something that is bad for you.”

The different mechanisms explain why cognition plays a much stronger role in taste and smell than in coughing in response to an irritant. It is possible, for example, to develop a taste for beer. But nobody learns not to cough; the response is rapid and largely automatic.

Scientists suspect these pulmonary neuroscretory cells contribute to the hypersensitivity of patients with COPD to airborne irritants. COPD is a group of diseases, including emphysema, that is characterized by coughing, wheezing, shortness of breath and chest tightness.

When the scientists looked at the airway tissues from patients with COPD, they discovered that they had more of these neurosecretory cells than airway tissues from healthy donors.

Ben-Shahar is hopeful that the PNEC pathways will provide targets for drugs that would better control asthma, COPD and other respiratory diseases. They would be welcome. There has been a steep rise in these diseases in the past few decades, treatment options have been limited, and there are no cures.

The research appears in the March issue of the American Journal of Respiratory Cell and Molecular Biology.

You May Like

China’s Influence Grows With New Infrastructure Bank

Multibillion-dollar China-backed and BRICS-supported Asian Infrastructure Investment Bank seen as possible challenger to such lenders as IMF, World Bank More

Video Rabbi Hits Road to Heal Jewish-Muslim Relations in France

Rabbi Michel Serfaty makes the rounds in his friendship bus to encourage dialogue and break down barriers between the two groups More

Post-deal Iran Leaders Need 'Economic Momentum' to Solidify

Economists say deal could inject more than $100 billion into coffers - not enough to entirely rescue ailing economy - but maybe adequate to create 'economic momentum' More

This forum has been closed.
Comments
     
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
US Gay Marriage Ruling Yields Real-life Impacti
X
Michael Bowman
June 28, 2015 10:05 PM
Friday’s landmark Supreme Court decision legalizing same-sex marriage throughout the United States is an outcome few thought possible just years ago, and shows a nation that increasingly tolerates and even celebrates the hopes and aspirations of gay people. VOA’s Michael Bowman spoke to a same-sex couple that will benefit from the high court ruling, and to a Christian scholar who is apprehensive about its potential consequences for America’s faith community.
Video

Video US Gay Marriage Ruling Yields Real-life Impact

Friday’s landmark Supreme Court decision legalizing same-sex marriage throughout the United States is an outcome few thought possible just years ago, and shows a nation that increasingly tolerates and even celebrates the hopes and aspirations of gay people. VOA’s Michael Bowman spoke to a same-sex couple that will benefit from the high court ruling, and to a Christian scholar who is apprehensive about its potential consequences for America’s faith community.
Video

Video Syrians Flee IS Advance in Hasaka

The Syrian government said Monday it has taken back one of several districts in Hasaka overrun by Islamic State militants. But continued fighting elsewhere in the northern city has forced thousands of civilians from their homes. In this report narrated by Bill Rodgers, VOA Kurdish Service reporter Zana Omer describes the scene in Amouda, where some of the displaced are taking refuge.
Video

Video Rabbi Hits Road to Heal Jewish-Muslim Relations in France

France is on high alert after last week's terrorist attack near the city Lyon, just six months after deadly Paris shootings. The attack have added new tensions to relations between French Jews and Muslims. France’s Jewish and Muslim communities also share a common heritage, though, and as far as one French rabbi is concerned, they are destined to be friends. From the Paris suburb of La Courneuve, Lisa Bryant reports about Rabbi Michel Serfaty and his friendship bus.
Video

Video S. Korea Christians Protest Gay Rights Festival

The U.S. Supreme Court decision mandating marriage equality nationwide has energized gay rights supporters around the world. Gay rights remain a highly contentious issue in a key U.S. ally, South Korea, where police did a deft job Sunday of preventing potential clashes between Christian protesters and gay activists. Kurt Achin reports from Seoul.
Video

Video Saudi Leaks Expose ‘Checkbook Diplomacy’ In Battle With Iran

Saudi Arabia’s willingness to wield its oil money on the global diplomatic stage appears to have been laid bare, after the website WikiLeaks published tens of thousands of leaked cables from Riyadh’s Ministry of Foreign Affairs. VOA's Henry Ridgwell reports.
Video

Video Nubians in Kenya Face Land Challenges

East Africa's ethnic Nubians have a rich cultural history that dates back thousands of years, but in Kenya they are facing hardships, including the loss of lands they have lived on for generations. They say the government has reneged on its pledge to award them title deeds for the plots. VOA's Lenny Ruvaga reports.
Video

Video Syrian Refugees Return to Tal Abyad

Syrian refugees in Turkey confirm they left their hometown of Tal Abyad because of intense fighting and coalition airstrikes, not because Kurdish fighters were engaged in ethnic cleansing, as some Turkish officials charged. VOA Kurdish Service reporter Zana Omer, in Tal Abyad, finds that civilians coming back to the town agree, as we hear in this report narrated by Roger Wilkison.
Video

Video Military Experts Question New Russian Tank Capabilities

Russia has been showing off its new tank design – the Armata T-14. Designers claim it is 20 years ahead of current Western designs - and driving it feels like playing a computer game. But military analysts question those assertions, and warn the cost could be too heavy a burden for Russia’s struggling economy. Henry Ridgwell reports.
Video

Video In Kenya, Police Said to Shoot First, Ask Questions Later

An organization that documents torture and extrajudicial killings says Kenyan police were responsible for 1,252 shooting deaths in five cities, including Nairobi, between 2009 and 2014, representing 67 percent of all gun deaths in the areas reviewed. Gabe Joselow has more from Nairobi.
Video

Video In Syrian Crisis, Social Media Offer Small Comforts

Za’atari, a makeshift city in Jordan, may be the only Syrian refugee camp to tweet its activities, in an effort to keep donors motivated as the war in Syria intensifies and the humanitarian crisis deepens. Inside the camp, families say mobile phone applications help hold together families that are physically torn apart. VOA’s Heather Murdock reports.
Video

Video Chemical-Sniffing Technology Fights Australia's Graffiti Vandals

Cities and towns all over the world spend huge amounts of resources battling graffiti writers who deface buildings, public transport vehicles and even monuments. Authorities in Sydney, Australia, hope a new chemical-sniffing technology finally will stop vandals from scribbling on walls in the passenger areas of commuter trains. VOA’s George Putic has more.
Video

Video Cambodia Struggling to Curb Child Labor

Earlier this year a United Nations report found 10 percent of Cambodian children aged 7-14 are working – one of the highest rates in the region – and said one in four children in that age bracket are forced to quit school to help their families. Although the child labor rate has dropped over the past decade, Cambodia has a lot more to do – including keeping more children in school. Robert Carmichael reports for VOA from Phnom Penh.

VOA Blogs