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

Video Russia’s Syrian Escalation Tests Obama’s Crisis Response

Critics once again question whether president has been slow to act on Syrian conflict, thus creating opening for powers like Russia More

Ancient African DNA Shows Mass Migration Back Into Africa

First genetic analysis of ancient human remains in Africa suggests massive migration from north around time of Egyptian empire More

NASA: Pluto Has Blue Sky

New photos also reveal the presence of water ice More

This forum has been closed.
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.
Hungary Criticized for Handling of Refugeesi
Henry Ridgwell
October 08, 2015 8:02 PM
Amnesty International has accused Hungary of breaking multiple international and European human rights laws in its handling of the refugee crisis. As Henry Ridgwell reports, thousands of migrants and refugees continue to travel through the Balkans to Hungary every day.

Video Hungary Criticized for Handling of Refugees

Amnesty International has accused Hungary of breaking multiple international and European human rights laws in its handling of the refugee crisis. As Henry Ridgwell reports, thousands of migrants and refugees continue to travel through the Balkans to Hungary every day.

Video Iraqi-Kurdish Teachers Vow to Continue Protest

Sixteen people were injured when police used tear gas and rubber bullets to disperse teachers and other public employees who took to the streets in Iraq’s Kurdish north, demanding their salaries from the Kurdish Regional Government (KRG). VOA’s Dilshad Anwar, in Sulaimaniya, caught up with protesting teachers who say they have not been paid for three months. Parke Brewer narrates his report.

Video Syrian Village Community Faces Double Displacement in Lebanon

Driven by war from their village in southwestern Syria, a group of families found shelter in Lebanon, resettling en masse in a half-built university to form one of the biggest settlements of its kind in Lebanon. Three years later, however, they now face being kicked out and dispersed in a country where finding shelter as a refugee can be especially tough. John Owens has more for VOA from the city of Saida, also known as Sidon.

Video Bat Colony: Unusual Tourist Attraction in Texas

The action hero Batman might be everyone’s favorite but real bats hardly get that kind of adoration. Put more than a million of these creatures of the night together and it only evokes images of horror. Sarah Zaman visited the largest urban bat colony in North America to see just how well bat and human get along with each other.

Video Device Shows Promise of Stopping Motion Sickness

It’s a sickening feeling — the dizziness, nausea and vomiting that comes with motion sickness. But a device now being developed could stop motion sickness by suppressing certain signals in the brain. VOA’s Deborah Block reports.

Video Making a Mint

While apples, corn, and cranberries top the list of fall produce in the US, it’s also the time to harvest gum, candy, and toothpaste—or at least the oil that makes them minty fresh. Erika Celeste reports from South Bend, Indiana on the mint harvest.

Video Activists Decry Lagos Slum Demolition

Acting on a court order, authorities in Nigeria demolished a slum last month in the commercial capital, Lagos. But human rights activists say the order was illegal, and the community was razed to make way for a government housing project. Chris Stein has more from Lagos.

Video TPP Agreed, But Faces Stiff Opposition

President Barack Obama promoted the Trans-Pacific Partnership on Tuesday, one day after 12 Pacific Rim nations reached the free trade deal in Atlanta. The controversial pact that would involve about 40 percent of global trade still needs approval by lawmakers in respective countries. Zlatica Hoke reports Obama is facing strong opposition to the deal, including from members of his own party.

Video Ukranian Artist Portrays Putin in an Unusual Way

As Russian President Vladimir Putin was addressing the United Nations in New York last month, he was also being featured in an art exhibition in Washington. It’s not a flattering exhibit. It’s done by a Ukrainian artist in a unique medium. And its creator says it’s not only a work of art - it’s a political statement. VOA’s Tetiana Kharchenko has more.

Video Nano-tech Filter Cleans Dirty Water

Access to clean water is a problem for hundreds of millions of people around the world. Now, a scientist and chemical engineer in Tanzania (in East Africa) is working to change that by creating an innovative water filter that makes dirty water safe. VOA’s Deborah Block has the story.

Video Demand Rising for Organic Produce in Cambodia

In Cambodia, where rice has long been the main cash crop, farmers are being encouraged to turn to vegetables to satisfy the growing demand for locally produced organic farm products. Daniel de Carteret has more from Phnom Penh.

Video Botanists Grow Furniture, with Pruning Shears

For something a bit out of the ordinary to furnish your home, why not consider wooden chairs, crafted by nature, with a little help from some British botanists with an eye for design. VOA’s Jessica Berman reports.

VOA Blogs