Evidence for epinephrine-induced depolarization in neurons of bullfrog sympathetic ganglia.
The response to epinephrine (EP) was determined for neurons in bullfrog sympathetic ganglia by intracellular and voltage-clamp recording techniques. EP (5 microM-1 mM) produced a concentration-dependent depolarization mediated through beta-adrenoceptors. The EP-induced depolarization (EPD) was associated with a decrease in the membrane conductance. The EP-induced current (EP1) was decreased at hyperpolarizing potential levels and nullified at -70 mV. No reversal of the EPI polarity was seen. It is concluded that the EPD is generated by the suppression of a voltage-dependent gK, probably the M-channel.
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D004594:Electrophysiology; D004837:Epinephrine / Q000494:pharmacology*; D005728:Ganglia, Sympathetic / Q000187:drug effects / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects; D011892:Rana catesbeiana; D011941:Receptors, Adrenergic / Q000187:drug effects / Q000502:physiology
D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists; D011941:Receptors, Adrenergic; D004837:Epinephrine