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

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

Lebanese Media Unite to Support Palestinians in Gaza

Joint newscast billed as Arab world’s first unified news bulletin in support of Hamas-controlled Gaza Strip More

Photogallery Australian PM Alleges ‘Coverup’ at MH17 Crash Site

Meanwhile, Russia's ambassador to Malaysia denies plane's black boxes were opened before they were handed over to Malaysian officials More

Despite Advances in AIDS Treatment, Stigma Lingers

Leading immunologist tells VOA that stigma is often what prevents those infected with disease from seeking treatment 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.
Nature of Space Exploration Enters New Agei
X
Elizabeth Lee
July 20, 2014 2:36 AM
Forty-five years ago this month, the first humans walked on the moon. It was during an era of the space race between the United States and the Soviet Union. World politics have changed since then and -- as Elizabeth Lee reports -- so has the nature of space exploration.
Video

Video Nature of Space Exploration Enters New Age

Forty-five years ago this month, the first humans walked on the moon. It was during an era of the space race between the United States and the Soviet Union. World politics have changed since then and -- as Elizabeth Lee reports -- so has the nature of space exploration.
Video

Video Chicago’s Argonne Lab Developing Battery of the Future

In 2012, the U.S. Department of Energy’s Office of Science awarded a $120 million grant to a new technology center focused on battery development - headquartered at Argonne National Laboratory in suburban Chicago, Illinois. As VOA’s Kane Farabaugh reports, there scientists are making the next technological breakthroughs in energy storage.
Video

Video In NW Pakistan, Army Offensive Causes Massive Number of Displaced

Pakistan’s army offensive in North Waziristan has resulted in the large-scale displacement of the local population. VOA's Ayaz Gul reports from northwest Pakistan where authorities say around 80 percent of the estimated 1 million internally displaced persons [IDPs] have settled in Bannu district, while much of the remaining 20 percent are scattered in nearby cities.
Video

Video Kurdish Peshmerga Force Secures Kirkuk, Its Oil

The Kurdistan regional government has sent its Peshmerga troops into the adjacent province of Kirkuk to drive out insurgents, and to secure the area's rich oil fields. By doing this, the regional government has added a fourth province to the three it officially controls. The oil also provides revenue that could make an independent Kurdistan economically strong. VOA’s Jeffrey Young went out with the Peshmerga and filed this report.
Video

Video Malaysia Reeling: Second Air Disaster in Four Months

Malaysia is reeling from the second air disaster in four months involving the country’s flag carrier. Flight 340 vanished in March and despite an extensive search, no debris has been found. And on Thursday, Flight 17, likely hit by a surface-to-air missile, came apart over eastern Ukraine. The two incidents together have left more than 500 people dead. VOA Correspondent Steve Herman reports from Kuala Lumpur.
Video

Video Diplomatic Crisis Grows Over MH17 Plane Crash

The Malaysia Airlines crash in eastern Ukraine is drawing reaction from leaders around the world. With suspicions growing that a surface-to-air missile shot down the aircraft, there are increasing tensions in the international community over who is to blame. Henry Ridgwell reports for VOA from London.
Video

Video Undocumented Immigrants Face Perilous Journey to US, No Guarantees

Every day, hundreds of undocumented immigrants from Central America attempt the arduous journey through Mexico and turn themselves over to U.S. border patrol -- with the hope that they will not be turned away. But the dangers they face along the way are many, and as Ramon Taylor reports from the Rio Grande Valley in Texas, their fate rests on more than just the reception they get at the US border.
Video

Video Scientists Create Blackest Material Ever

Of all the black things in the universe only the infamous "black holes" are so black that not even a tiny amount of light can bounce back. But scientists have managed to create material almost as black, and it has enormous potential use. VOA’s George Putic has more.
Video

Video Fog Collector Transforming Maasai Water Harvesting in Kenya

The Maasai people of Kenya are known for their cattle-herding, nomadic lifestyle. But it's an existence that depends on access to adequate water for their herds and flocks. Lenny Ruvaga reports for VOA, on a "fog collector."

AppleAndroid