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When you think about the sense of taste, you probably think about your mouth and the taste buds on your tongue. These taste buds gather flavors and send signals to the brain to help you tell the difference between foods that are sweet, sour, salty, savory, and bitter. Now researchers at the University of Maryland School of Medicine in Baltimore have discovered a surprising collection of taste receptors inside human lungs that could open up new avenues of research to help prevent or reduce the symptoms of asthma attacks.
Air moves in and out of the lungs through tubes that are known as airways. These airways are made up of smooth muscle tissue that can contract and expand like other muscles in the body. For people with asthma, these smooth muscles in the airway sometimes suddenly contract or tighten which makes the opening in the airway smaller so it is harder for air to move in and out of the lungs. An asthma attack can cause wheezing and shortness of breath, while a severe attack can completely close the airway and prevent breathing.
Medications are available to help relieve the symptoms of an asthma attack by reopening the airways, but researchers are constantly looking for better ways to control asthma symptoms. This was the case with the researchers in Maryland who were conducting an unrelated study of the muscle receptors in the lungs that regulate when the airways constrict and relax. Stephen B. Liggett, M.D., professor of physiology at the University of Maryland School of Medicine and senior author of the study said the team discovered the taste receptors in the lungs by accident. "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," Liggett said.
The taste receptors found in the lungs are the same as those found on the tongue that detect bitterness. In the lungs, the taste receptors are not clustered together into taste buds and do not send taste sensations to the brain like their counterparts on the tongue. But they do respond to things that have a bitter taste.