Editing Bronchospasm (section)

===Muscarinic Acetylcholine receptor antagonist===
{{see also|Parasympathetic nervous system|Sympathetic nervous system}}

The [[neurotransmitter]] [[acetylcholine]] is known to decrease sympathetic response by slowing the heart rate and constricting the [[smooth muscle tissue]]. Ongoing research and successful clinical trials have shown that agents such as [[diphenhydramine]], [[atropine]] and [[ipratropium bromide]] (all of which act as [[receptor antagonist]]s of [[muscarinic acetylcholine receptor]]s) are effective for treating asthma and COPD-related symptoms.<ref>{{cite journal |last1=Moulton |first1=Bart C |last2=Fryer |first2=Allison D |title=Muscarinic receptor antagonists, from folklore to pharmacology; finding drugs that actually work in asthma and COPD |journal=British Journal of Pharmacology |date=May 2011 |volume=163 |issue=1 |pages=44–52 |doi=10.1111/j.1476-5381.2010.01190.x |language=en |issn=0007-1188|doi-access=free |pmid=21198547 |pmc=3085867 }}</ref>