[Changes in the intracellular calcium concentration and transmembrane currents, evoked by iontophoretic injections of cyclic AMP, in Helix pomatia neurons].
Transmembrane currents and intracellular concentration of free Ca2+ were measured in voltage-clamped isolated neurons of Helix pomatia following the injection of cAMP. In most neurons in the range of membrane potentials from -40 to -100 mV cAMP injection induced both inward current and a long-lasting increase in [Ca2+]in. In the Ca-free external medium and after addition of EGTA (a Ca chelator) to it, the cAMP-induced inward current and [Ca2+]in increase remained unchanged. In most cases in Na-free external solution the cAMP-induced inward current markedly decreased, whereas [Ca2+]in changes remained as it were. Cd2+ (2 mM) did not affect the cAMP-induced current and [Ca2+]in increase. Both procaine++ and ryanodine (inhibitors of Ca release from intracellular stores) did not change the cAMP-induced effects. La3+ (1 mM) blocked both the inward current and an increase of [Ca2+]in. Obtained data confirm the hypothesis of cAMP-mediated Ca release from the intracellular stores.
Belian
P V
PV
Mironov
S L
SL
Osipenko
O N
ON
Tepikin
A V
AV
D000818:Animals; D002118:Calcium / Q000378:metabolism* / Q000494:pharmacology; D000242:Cyclic AMP / Q000494:pharmacology*; D006372:Helix, Snails / Q000378:metabolism / Q000502:physiology*; D066298:In Vitro Techniques; D007478:Iontophoresis; D008564:Membrane Potentials / Q000187:drug effects; D009474:Neurons / Q000378:metabolism / Q000502:physiology*; D011343:Procaine / Q000494:pharmacology; D012433:Ryanodine / Q000494:pharmacology; D012964:Sodium / Q000494:pharmacology
D012433:Ryanodine; D011343:Procaine; D012964:Sodium; D000242:Cyclic AMP; D002118:Calcium
Izmeneniia vnutrikletochnoĭ kontsentratsii kal'tsiia transmembrannykh tokov, vyzvannye ionoforeticheskoĭ in"ektsieĭ tsAMF, v neĭronakh vinogradnoĭ ulitki.