A team headed by Stephen B. Liggett of University of Maryland School of Medicine has discovered that lungs actually have bitter taste receptors on the smooth muscle of the bronchus. The fascinating part is that bitter compounds opened up the airways substantially more effectively than available drugs for asthma and COPD.
The taste receptors in the lungs are the same as those on the tongue. The tongue’s receptors are clustered in taste buds, which send signals to the brain. The researchers say that in the lung, the taste receptors are not clustered in buds and do not send signals to the brain, yet they respond to substances that have a bitter taste.
For the current study, Dr. Liggett’s team exposed bitter-tasting compounds to human and mouse airways, individual airway smooth muscle cells, and to mice with asthma.
Most plant-based poisons are bitter, so the researchers thought the purpose of the lung’s taste receptors was similar to those in the tongue – to warn against poisons.
The researchers tested a few standard bitter substances known to activate these receptors. “It turns out that the bitter compounds worked the opposite way from what we thought,” says Dr. Liggett. “They all opened the airway more extensively than any known drug that we have for treatment of asthma or chronic obstructive pulmonary disease (COPD).” Dr. Liggett says this observation could have implications for new therapies. “New drugs to treat asthma, emphysema or chronic bronchitis are needed,” he says. “This could replace or enhance what is now in use, and represents a completely new approach.”
More from University of Maryland’s special page about the research…
Press release: WHEN BAD TASTES GOOD: DISCOVERY OF TASTE RECEPTORS IN THE LUNGS COULD HELP PEOPLE WITH ASTHMA BREATHE EASIER…
Article abstract in Nature Medicine: Bitter taste receptors on airway smooth muscle bronchodilate by localized calcium signaling and reverse obstruction