Soman enhances nicotinic depolarizations, and depresses muscarinic hyperpolarizations in parasympathetic neurons.
Intracellular recording techniques were used to study the action of an irreversible anticholinesterase, soman, on cholinergic transmission in cat bladder parasympathetic neurons. With soman (0.1-10 microM) treatment, nicotinic depolarizations were increased in amplitude and prolonged in duration, whereas muscarinic hyperpolarizations showed either a depressed amplitude and prolonged duration, or were completely blocked. These data suggest that the final result of soman action is different at nicotinic and muscarinic receptor-channel complexes in parasympathetic neurons.
Kumamoto
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Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston 77550.
Shinnick-Gallagher
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P
D000818:Animals; D002110:Caffeine / Q000494:pharmacology; D002415:Cats; D004558:Electric Stimulation; D005071:Evoked Potentials / Q000187:drug effects; D005726:Ganglia, Parasympathetic / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D008464:Mecamylamine / Q000494:pharmacology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D010646:Phentolamine / Q000494:pharmacology; D011976:Receptors, Muscarinic / Q000502:physiology*; D011978:Receptors, Nicotinic / Q000502:physiology*; D012016:Reference Values; D012999:Soman / Q000494:pharmacology*; D001743:Urinary Bladder / Q000294:innervation*
D011976:Receptors, Muscarinic; D011978:Receptors, Nicotinic; D002110:Caffeine; D008464:Mecamylamine; D012999:Soman; D010646:Phentolamine