Anticholinergic effect in the lung

Anticholinergic effects in the lung

Vagal stimulation of the respiratory tract's muscarinic-3 receptors causes airway constriction. By blocking this parasympathetic stimulation, the anticholinergic agents reduce ASM tone and lead to dilatation of the constricted airway.

There are three principle muscarinic (M) receptors: M1=postganglionic and CNS, M2=postsynaptic in heart nodes and myocard, and M3=postsynaptic in smooth muscle, vascular endothelium and secretory glands. The M4 stimulates molecular mechanisms like the M2receptors but its function is unclear. The M5 receptor is like the M1 receptor and is also found in the CNS, but its role is elusive.


The anticholinergic agents are the inhaled bronchodilators of first choice in asthma.


Anticholinergic agents are airway specific.