The “nicotinic” and “muscarinic” receptors of the urinary bladder of the guinea-pig

Abstract The action of acetylcholine and nicotine on the urinary bladder of the guinea-pig has been examined using three techniques of physiological denervation. Nicotine was neurogenic and equiactive concentrations of acetylcholine were myogenic. Whilst acetylcholine has both “muscarinic” and “nicotinic” effects on the guinea-pig bladder, the concentration required to stimulate the nicotinic receptors was approximately 100 times that required for the muscarinic receptors. These results indicate that the nicotinic receptors are confined to nervous tissue, and do not support the suggestion that there might be non-neuronal nicotinic receptors in the bladder musculature of the guinea-pig. The possibility of a non-cholinergic component in the post-ganglionic parasympathetic fibres to the bladder should still be considered.