[The effect of intracellular calcium on an increase in the cAMP-mediated calcium current].
Intracellularly perfused neurons of Helix pomatia in which serotonin-induced increase of calcium current (Ica) is mediated by cAMP were studied by the voltage clamp technique. It was established that an increase of the calcium intracellular concentration ([Ca2+]i) caused inhibition of the serotonin (5-HT) effect. The 5-HT effect value at 10(-6) and 10(-7) mol/l [Ca2+]i was 60 and 32% of the control one, respectively. Addition of the calmodulin antagonist (5.10(-5) M trifluoperasine) and phosphodiesterase blockers (5 mM theophylline or 10(-4) mol/l IBMX) sharply reduced the Ca2+ ability to inhibit the 5-HT effect. It is concluded that the Ca(2+)-calmodulin-dependent phosphodiesterase is a key link in the interaction between two signal transduction pathways--Ca2+ and cAMP in modulation of the calcium channel activity.
Luk'ianets
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EA
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D015761:4-Aminopyridine / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000502:physiology*; D015220:Calcium Channels / Q000187:drug effects / Q000502:physiology*; D003404:Creatinine / Q000494:pharmacology; D000242:Cyclic AMP / Q000502:physiology*; D004338:Drug Combinations; D004347:Drug Interactions; D004533:Egtazic Acid / Q000494:pharmacology; D006372:Helix, Snails; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D012701:Serotonin / Q000494:pharmacology; D013806:Theophylline / Q000494:pharmacology; D014268:Trifluoperazine / Q000494:pharmacology
D015220:Calcium Channels; D004338:Drug Combinations; C014050:creatinine sulfate, serotonin drug combination; D014268:Trifluoperazine; D012701:Serotonin; D004533:Egtazic Acid; D003404:Creatinine; D015761:4-Aminopyridine; D013806:Theophylline; D000242:Cyclic AMP; D002118:Calcium; D015056:1-Methyl-3-isobutylxanthine
Issledovanie vliianiia vnutrikletochnogo kal'tsiia na uvelichenie kal'tsievogo toka, oposredovannoe tsAMF.