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Volatile anaesthetics inhibit a cyclic AMP‐dependent sodium‐potassium current in cultured sensory neurones of bullfrog
Author(s) -
Tokimasa T.,
Sugiyama K.,
Akasu T.,
Muteki T.
Publication year - 1990
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1990.tb12111.x
Subject(s) - bullfrog , biophysics , forskolin , depolarization , chemistry , membrane potential , hyperpolarization (physics) , reversal potential , adenosine , conductance , medicine , electrophysiology , endocrinology , patch clamp , biochemistry , stereochemistry , biology , in vitro , mathematics , combinatorics , nuclear magnetic resonance spectroscopy
1 Cultured dorsal root ganglion cells of the bullfrog were voltage‐clamped in the whole‐cell configuration. 2 An adenosine 3′:5′‐cyclic monophosphate (cyclic AMP)‐dependent cationic inward rectifier (I H ) was inhibited by bath application of enflurane (0.2‐0.8 m m ) and halothane (0.2‐0.5 m m ), which thereby induced an outward current at the resting potential, and a membrane hyperpolarization in undamped cells. 3 The main effect of enflurane (0.5 m m ) was to displace the steady‐state I H activation curve to a hyperpolarizing direction by about 10 mV, as well as to reduce the maximum H‐conductance to about 20%. 4 Forskolin (1–10 μ m ), which enhances I H by producing a depolarizing shift in the I H activation curve and increasing the maximum H‐conductance, recruited I H even when the current had already been eliminated by enflurane (1 m m ).