[The "trap"--a modification of the block of neuronal nicotinic cholinoceptors].
The effect of IEM-1742, a pentaethonium derivative, on the currents induced by iontophoretic applications of acetylcholine was studied in rat superior cervical ganglion neurons using patch-clamp method in the whole-cell modification. Blocking action increased with membrane hyperpolarization and was removed by strong membrane depolarization. Apparent dissociation constant for the receptor-blocker reaction was found to be (2.9 +/- 0.6) 10(-6) M (n = 6) at -50 mV and 20-23 degrees C. IEM-1742 blocks the nicotinic acetylcholine receptor in its activated form. The dissociation of IEM-1742 from the receptor was drastically accelerated during its activation by agonist (trap-block). Trapped receptor was not released from the blocker only by membrane depolarization to the level at which any blocking effect is absent. The data obtained show that IEM-1742 in rat sympathetic ganglion neurons acts in the potential-dependent manner and displays a trap-effect.
Kurennyĭ
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Derkach
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Gmiro
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Skok
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D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D004347:Drug Interactions; D005728:Ganglia, Sympathetic / Q000187:drug effects / Q000502:physiology; D008564:Membrane Potentials / Q000187:drug effects; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology; D051381:Rats; D011978:Receptors, Nicotinic / Q000187:drug effects* / Q000502:physiology
D000644:Quaternary Ammonium Compounds; D011978:Receptors, Nicotinic; C059801:IEM 1742; D000109:Acetylcholine
"Lovushka"--raznovidnost' bloka neĭronnykh nikotinovykh kholinoretseptorov.