Chlorine Triggers Protective Nerve Receptor

Apr 09, 2008
Chlorine Triggers Protective Nerve Receptor
Airway nerve cells exposed to chlorine. Bright color indicates excitation of some nerve cells.

Inhaling chlorine triggers a nerve receptor that protects healthy people by inducing sneezing, coughing, and irritation, but can cause major problems for people with asthma and other respiratory problems, Yale School of Medicine researchers report today in the Journal of Clinical Investigation.

Prior to this study it was thought that chlorine and other oxidants induced pain and inflammation only through tissue injury. But the Yale team observed that mice lacking the receptor TRPA1 were insensitive to exposure to chlorine—which is used in industrial synthesis, for disinfection of drinking water and swimming pools, and in household bleach. Interestingly, the receptor is the same one triggered by pungent mustard and noxious chemicals in cigarette smoke.

“We show that chlorine activates a specific receptor, TRPA1, in pain-sensing nerve endings in the airways,” said corresponding author, Sven-Eric Jordt, assistant professor of pharmacology. “We identified a population of neurons that fire in response to chlorine exposure, inducing pain and irritation, and narrowing airway passages—probably to protect the lung from chlorine damage.”

The problem with this response, he said, is that people whose respiratory systems already are compromised by asthma or congestion from colds and allergies then have a hypersensitive response to chemicals—their lungs are already doing what the brain is telling the respiratory system to do to protect itself.

“In these patients chlorine and other TRPA1 activators can trigger constriction of the bronchial pathways, and cause pain and discomfort in the airways,” Jordt said.

The silver lining, said Jordt, is that the study points to TRPA1 as a promising new target for the development of new drugs to suppress coughs and relieve pain and inflammation.

The lead authors are Bret Bessac and Michael Sivula of Yale. The study was conducted in collaboration with the laboratory of Lauren Cohn in the pulmonary section of Internal Medicine at Yale and funded by grants from the National Institute of Environmental Health Sciences of the National Institutes of Health.

Source: Yale University

Explore further: Molecule enhances copper's lethal punch against microbes

add to favorites email to friend print save as pdf

Related Stories

Physicists discuss quantum pigeonhole principle

14 hours ago

The pigeonhole principle: "If you put three pigeons in two pigeonholes at least two of the pigeons end up in the same hole." So where's the argument? Physicists say there is an important argument. While the ...

Giant crater in Russia's far north sparks mystery

16 hours ago

A vast crater discovered in a remote region of Siberia known to locals as "the end of the world" is causing a sensation in Russia, with a group of scientists being sent to investigate.

NASA Mars spacecraft prepare for close comet flyby

17 hours ago

NASA is taking steps to protect its Mars orbiters, while preserving opportunities to gather valuable scientific data, as Comet C/2013 A1 Siding Spring heads toward a close flyby of Mars on Oct. 19.

Recommended for you

Breakthrough in understanding of important blood protein

11 hours ago

The human body contains a unique protein that has the unusual property of destroying itself after a few hours of existence - it must therefore be continually recreated and is no stable protein. The protein, ...

User comments : 0