to determine if postsynaptic muscarinic m-1 receptors mediate airway constriction , the action was compared of pirenzepine , that antagonizes selectively muscarinic m-1 receptors , and atropine , that blocks both muscarinic m-1 and m-2 receptors , on bronchial responses to methacholine inhalation in seven asthmatic patients .
C0004259
atropine
C0004096
asthmatic