Research has found that there are taste receptors in the lungs. This finding could lead to better ways of restoring breathing for asthma sufferers.
Studies using mice and human tissues showed that exposing the receptors to bitter substances cause them to signal constricted muscles in the lungs to relax.
Asthma attacks cause muscles in the lungs to tighten and the tubes that carry oxygen to the bloodstream to constrict. Bitter substances could reopen squeezed airways within seconds.
Dr. Norman H. Edelman, lead researcher and Chief Medical Officer at the American Lung Association, stressed that this is not a cure for the disease. It does, however, offer the possibility for alternative asthma inhalers.
Current inhalers act on the beta 2 adrenergic receptor in the lungs. The newly discovered pulmonary ‘taste buds’ do not communicate with the brain like those on the tongue, but rather with muscle cells. Exposing lung muscle to bitter aerosols expanded airways to 90% of their original volume, at 3 times the speed produced by the beta 2 agonist inhalant.
Such a response to bitter substances is unexpected, especially because bitterness is usually indicative of toxicity.
Researchers speculate that these receptors evolved in response to pneumonia or bronchitis, the culpable bacteria for which secrete a bitter substance that would have triggered airways to stay open, allowing patients to cough and thus speeding up recovery.
The results could have potential for developing new approaches to asthma, emphysema and chronic bronchitis. The study was published in the journal Nature Medicine.