Odor Receptors Discovered Inside Human Lungs
Noses are not the only part of the body that can sense odors, but lungs also have receptors that can perform the same job as nose, researchers have found.
Scientists at Washington University in St. Louis and the University of Iowa discovered that unlike the receptors in the nose, that are located in the membranes of nerve cells, receptors in lungs resided in the membranes of neuroendocrine cells. Therefore, the lung’s odor receptors instead sending nerve impulses to brain, they trigger the flask-shaped neuroendocrine cells to dump hormones that can make the airways constrict.
“We forget that our body plan is a tube within a tube, so our lungs and our gut are open to the external environment. Although they’re inside us, they’re actually part of our external layer. So they constantly suffer environmental insults and it makes sense that we evolved mechanisms to protect ourselves," said the lead researchers Yehuda Ben-Shahar, PhD, assistant professor of biology, in Arts & Sciences, and of medicine at Washington University in St. Louis in a press release.
Researchers also suggested that the odor receptors on the cells might be a therapeutic target and by blocking them it might be possible to prevent few attacks. This opens up a possibility for allowing people to cut down on the use of steroids or bronchodilators.
“When people with airway disease have pathological responses to odors, they’re usually pretty fast and violent,” added Ben-Shahar. “Patients suddenly shut down and can’t breathe, and these cells may explain why.”
Ben-Shahar also noted the deferences that existed between chemosensation in the nose and in the lung. Generally the cells in the nose are neurons which are narrowly tuned receptor. They expect that these signals might be woven together in the brain to interpret the odor.
The research is published in the American Journal of Respiratory Cell and Molecular Biology.