Cyclic AMP analog activates Na(+)-dependent inward currents in dissociated frog motoneurons.
Effects of intracellular accumulation of 3',5'-cyclic adenosine monophosphate (cAMP) were studied using 3',5'-cyclic 8-bromoadenosine monophosphate (8-Br-cAMP) and forskolin on single motoneurons acutely dissociated from adult bullfrog spinal cord. 8-Br-cAMP (10(-3) M) and forskolin (1.5 x 10(-6) M) activated inward currents under K(+)-free conditions at a holding potential of -70 mV. The currents were dependent on extracellular Na+ concentration, and were never reversed within the range of membrane potentials tested (-130 to 30 mV). These results indicate that accumulation of intracellular cAMP induces Na(+)-dependent inward currents in frog motoneurons.
Adachi
S
S
Department of Toxicology and Pharmacology, Faculty of Pharmaceutical Sciences, University of Tokyo, Japan.
Oka
J
J
Nagao
T
T
Fukuda
H
H
D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology*; D000818:Animals; D005576:Colforsin / Q000494:pharmacology*; D000242:Cyclic AMP / Q000378:metabolism*; D066298:In Vitro Techniques; D007700:Kinetics; D008564:Membrane Potentials / Q000187:drug effects; D009046:Motor Neurons / Q000187:drug effects / Q000502:physiology*; D011188:Potassium / Q000494:pharmacology; D011892:Rana catesbeiana; D015222:Sodium Channels / Q000187:drug effects / Q000502:physiology*
D015222:Sodium Channels; D005576:Colforsin; D015124:8-Bromo Cyclic Adenosine Monophosphate; D000242:Cyclic AMP; D011188:Potassium