Salivatory effects induced by pirenzepine, atropine, metacine and hexamethonium in preganglionar chronically denervated human parotid gland

Abstract

Abstract Both classical (atropine) and non-traditional (pirenzepine, metacine) antagonists of the muscarinic cholinoreceptors induce, rather than block, an intense and prolonged salivary response in chronically denervated human parotid glands and thus are capable of discriminating between neuronal and aneuronal receptors. Hexamethonium (benzohexonium) a ganglion-blocking agent (0·4 mL, 2·5%) completely inhibits this paradoxical salivation to atropine, benzilylcholine (metacine) and pirenzepine in the chronic preganglionically denervated human parotid gland. The authors discuss the essence of the revealed paradoxical phenomena.