Related Experiment Video
Updated: May 5, 2026

Subcutaneous Administration of Muscarinic Antagonists and Triple-Immunostaining of the Levator Auris Longus Muscle in Mice
Published on: September 8, 2011
Muscarinic receptors in human airways
1Institute for Asthma and Allergy, Washington, DC 20010, USA.
Abstract:
Muscarinic receptors play a double role in airway disorders, mediating an increase in mucus secretion, as well as constriction of smooth muscle. Cholinergic activity of the lung is more pronounced in large than in peripheral airways; in the nose parasympathetic stimulation leads to hypersecretion and vasodilation. This article reviews the differences in muscarinic subreceptors in the upper and lower airways and discusses the effectiveness of anticholinergic agents in blocking parasympathetic stimulation at these sites.
Related Concept Videos
Cholinergic Receptors: Muscarinic
The subtypes M1, M3, and M5 couple with the Gq subunit and activate the phospholipase C (PLC) activity, mobilizing intracellular Ca2+....
Cholinergic Receptors: Nicotinic
There are two types of nicotinic receptors: neuromuscular (NM/NM/N1) and neuronal (NN/NN/N2). The two families differ based on their location and selectivity to...
Direct-Acting Cholinergic Agonists: Pharmacological Actions
Cholinergic Antagonists: Pharmacological Actions
Gastrointestinal Effects: Antimuscarinics reduce gut contractions, increase gastric emptying, and slow intestinal transit. They partly inhibit gastric acid secretion...
Cholinergic Antagonists: Therapeutic Uses
Respiratory Tract: Ipratropium, aclidinium, and tiotropium treat asthma, chronic bronchitis, and chronic obstructive pulmonary disease (COPD). They protect against bronchoconstriction caused by irritants like cigarette smoke, sulfur dioxide, and ozone. They also help reduce nasopharyngeal...
Antiasthma Drugs: Muscarinic Receptor Antagonists
Antimuscarinic agents compete with ACh for the same binding site on the muscarinic receptors. By binding to these receptors, they inhibit the downstream effects of ACh and block the parasympathetic...

