Pancuronium and gallamine are antagonists for pre- and post-junctional muscarinic receptors in the guinea-pig lung

Naunyn Schmiedebergs Arch Pharmacol. 1987 Apr;335(4):367-71. doi: 10.1007/BF00165549.


The effects of atropine, pancuronium and gallamine were tested on pre- and post-junctional muscarinic receptors in the lung. Inhibition of bronchoconstriction induced by intravenous injection of acetylcholine (ACh) was used as a measure of post-junctional receptor blockade. All three antagonists reduced ACh-induced bronchoconstriction. The effects were dose-related for atropine and pancuronium and complete inhibition was obtained with 0.01 mg/kg and 10 mg/kg respectively. Gallamine was much less potent than the other two drugs; the inhibitory effect was not dose-related and never exceeded 50% even at a dose of 10 mg/kg. In contrast, blockade of pre-junctional inhibitory muscarinic receptors in pulmonary parasympathetic nerves by these three antagonists, produced potentiation of bronchoconstriction induced by vagal-nerve stimulation. Consequently, the effect of the three antagonists on vagally-induced bronchoconstriction is dependent on the balance between their pre- and post-junctional blocking activity. Gallamine was the most effective and atropine the least effective antagonist for potentiating nerve-induced bronchoconstriction. At doses which produce 100% neuromuscular blockade, both pancuronium (0.04 mg/kg) and gallamine (4 mg/kg) potentiated vagally-induced bronchoconstriction. At these doses, pancuronium doubled and gallamine caused a four-fold increase in vagally-induced bronchoconstriction, despite partial concurrent blockade of muscarinic receptors in the smooth muscle of the airways.

MeSH terms

  • Acetylcholine / pharmacology
  • Animals
  • Atropine / pharmacology
  • Bronchi / drug effects
  • Electric Stimulation
  • Gallamine Triethiodide / pharmacology*
  • Guinea Pigs
  • Heart Rate / drug effects
  • In Vitro Techniques
  • Lung / drug effects
  • Lung / innervation*
  • Male
  • Pancuronium / pharmacology*
  • Parasympathetic Nervous System / physiology
  • Parasympatholytics*
  • Receptors, Muscarinic / drug effects*


  • Parasympatholytics
  • Receptors, Muscarinic
  • Atropine
  • Pancuronium
  • Acetylcholine
  • Gallamine Triethiodide