The airways to the lungs react to fruity and floral scents.
Olfactory receptors have been detected in the muscle cells of the bronchi — the tubes that send air to the lungs. According to a study published in Frontiers in Physiology, the finding could offer a new approach for asthma therapy.
The researchers identified the two olfactory receptors in bronchi muscle cells that had been obtained from donors and then cultured in the lab.
Like the ones in your nose, the olfactory receptors in the bronchi were found to be sensitive to certain chemical compounds. The first, OR2AG1, responds to amyl butyrate, which is a fruity scent with banana and apricot notes. The second, OR1D2, detects scents with floral and oily notes, like the common perfume ingredient called bourgeonal (the synthetic odor for lily-of-the-valley).
But unlike the receptors in your nose, these ones don’t trigger your brain to perceive the smell of flowers or fruits. Rather, the researchers determined that the bronchi olfactory receptors can cause a person’s airway to either relax or contract.
The finding that OR2AG1 dilates in response to amyl butyrate “may help improve airflow in asthma sufferers," says study lead author Hanns Hatt, from Ruhr-University Bochum in Germany, in a press release. "It can probably counteract not only the effect of histamine, but also that of other allergens that make breathing difficult."
On the other hand, when OR1D2 was hit with bourgeonal, not only did it cause the airway to seize up, but it also produced inflammatory substances. This finding might explain why some perfumes are known to act as respiratory irritants.
The researchers hope to further examine the role of olfactory receptors in respiratory conditions through studies on human subjects.