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 <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

    Clinton, Trump and the 'Woman’s Card'

    Ask supporters of Democratic front-runner in US presidential campaign, and they’ll tell you Republican presidential candidate is playing a dangerous hand

    Russian Censorship Group Seeks Chinese Help to Better Control Internet

    At recent Safe Internet League forum in Moscow, speakers from both nations underscored desire for authorities to further limit and control information online

    Video Makeshift Pakistani School Helps Slum Kids

    Free classes in Islamabad park serve a few of the country’s nearly 25 million out-of-school youths; NGO cites ‘education crisis’

    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.
    Turkish Kurd Islamist Rally Stokes Tensionsi
    X
    April 29, 2016 12:28 AM
    In a sign of the rising power of Islamists in Turkey, more than 100,000 people recently gathered in Diyarbakir, the main city in Turkey’s predominantly Kurdish southeast, to mark the birthday of the Prophet Muhammad. The gathering highlighted tensions with the pro-secular Kurdish nationalist movement. Dorian Jones reports from Diyarbakir.
    Video

    Video Turkish Kurd Islamist Rally Stokes Tensions

    In a sign of the rising power of Islamists in Turkey, more than 100,000 people recently gathered in Diyarbakir, the main city in Turkey’s predominantly Kurdish southeast, to mark the birthday of the Prophet Muhammad. The gathering highlighted tensions with the pro-secular Kurdish nationalist movement. Dorian Jones reports from Diyarbakir.
    Video

    Video Pakistani School Helps Slum Kids

    Master Mohammad Ayub runs a makeshift school in a public park in Islamabad. Thousands of poor children have benefited from his services over the years, but, as VOA's Ayesha Tanzeem reports, roughly 25 million school-age youths don't get an education in Pakistan.
    Video

    Video Florida’s Weeki Wachee ‘Mermaids’ Make a Splash

    Since 1947, ‘mermaids’ have fascinated tourists at central Florida’s Weeki Wachee Springs State Park with their fluid movements and synchronized ballet. Performing underwater has its challenges, including cold temperatures and a steady current, as VOA’s Lin Yang and Joseph Mok report.
    Video

    Video Somali, African Union Forces Face Resurgent Al-Shabab

    The Islamic State terror group claimed its first attack in Somalia earlier this week, though the claim has not been verified by forces on the ground. Meanwhile, al-Shabab militants have stepped up their attacks as Somalia prepares for elections later this year. Henry Ridgwell reports there are growing frustrations among Somalia’s Western backers over the country’s slow progress in forming its own armed forces to establish security after 25 years of chaos.
    Video

    Video Bangladesh Targeted Killings Spark Wave of Fear

    People in Bangladesh’s capital are expressing deep concern over the brutal attacks that have killed secular blogger, and most recently a gay rights activist and an employee of the U.S. embassy. Xulhaz Mannan, an embassy protocol officer and the editor of the country’s only gay and transgender magazine Roopban; and his friend Mehboob Rabbi Tanoy, a gay rights activist, were hacked to death by five attackers in Mannan’s Dhaka home earlier this month.
    Video

    Video Documentary Tells Tale of Chernobyl Returnees

    Ukraine this week is marking the 30th anniversary of the world's worst nuclear accident, at the Chernobyl nuclear power plant. Soviet officials at first said little about the accident, but later evacuated a 2,600-square-kilometer "exclusion zone." Some people, though, came back. American directors Holly Morris and Anne Bogart created a documentary about this faithful and brave community. VOA's Tetiana Kharchenko reports from New York on "The Babushkas of Chernobyl." Carol Pearson narrates.
    Video

    Video Nigerians Feel Bite of Buhari Economic Policy

    Despite the global drop in the price of oil, Nigerian President Muhammadu Buhari has refused to allow the country's currency to devalue, leading to a shortage of foreign exchange. Chris Stein reports from Lagos businessmen and consumers are feeling the impact as the country deals with a severe fuel shortage.
    Video

    Video  Return to the Wild

    There’s a growing trend in the United States to let old or underused golf courses revert back to nature. But as Erika Celeste reports from one parcel in Grafton, Ohio, converting 39 hectares of land back to green space is a lot more complicated than just not mowing the fairway.
    Video

    Video West Urges Unity in Libya as Migrant Numbers Soar

    The Italian government says a NATO-led mission aimed at stemming the flow of migrants from Libya to Europe could be up and running by July. There are concerns that the number of migrants could soar as the route through Greece and the Balkans remains blocked. Western powers say the political chaos in Libya is being exploited by people smugglers — and they are pressuring rival groups to come together under the new unity government. VOA's Henry Ridgwell reports.
    Video

    Video Russia’s TV Rain Swims Against Tide in Sea of Kremlin Propaganda

    Russia’s media freedoms have been gradually eroded under President Vladimir Putin as his government has increased state ownership, influence, and restrictions on critical reporting. Television, where most Russians get their news, has been the main target and is now almost completely state controlled. But in the Russian capital, TV Rain stands out as an island in a sea of Kremlin propaganda.

    Special Report

    Adrift The Invisible African Diaspora