Researchers Unexpectedly Identify Potential Causes of Asthma, COPD

Rockville, Md. (November 8, 2021)—The activation of muscarinic acetylcholine (M2) receptors could be one of the causes of diseases like asthma and chronic obstructive pulmonary disease (COPD), according to the findings of a new study in the journal Function. The novel results also show drugs that block these receptors could be used to treat these diseases. 

In this study, electrical stimulation of nerves in the airways resulted in constriction of airway smooth muscle. This effect depended on the activation of M3 receptors (receptors that cause smooth muscle contraction) because drugs that block these receptors abolished the constriction. However, researchers found that small alterations to the electrical stimulus parameters made a large difference to the level of constriction. For example, a reduction in the stimulus interval resulted in a doubling in the force of constriction. Researchers surprisingly discovered this effect was reversed by drugs that block M2 receptors and were absent in mice lacking M2 receptors. 

It appears that M2 muscarinic receptors make a much greater contribution to the constriction of the airways than previously understood. This indicates activation of M2 receptors on airway smooth muscle cells primes the muscle so that stimulation of M3 receptors constricts the airways to a greater degree when the M2 receptors are also activated. 

Read the full article, “Contribution of postjunctional M2 muscarinic receptors to cholinergic nerve-mediated contractions of murine airway smooth muscle,” published ahead of print in Function. Contact APS Media Relations or call 301.634.7314 to schedule an interview with a member of the research team.