Morphine and methadone have different effects on calcium channel currents in neuroblastoma cells.
Using patch-clamp technique, cellular calcium channel currents were studied on nine mouse neuroblastoma N1E115 cells. Both morphine and methadone decreased the T-type calcium currents in dose-dependent fashion. These effects were partially blocked by naloxane. On L-type calcium currents, morphine showed no effect. However, methadone inhibited the L-calcium currents in dose-dependent fashion. This effect was not antagonised by naloxone. Hence, the action of methadone on L-calcium channel is probably not associated with mu receptors.
Yang
J C
JC
Department of Anaesthesiology, The University of Hong Kong, Room 424, Block K, Queen Mary Hospital, Pokfulam Road, Hong Kong, Hong Kong.
Shan
J
J
Ng
K F
KF
Pang
P
P
D000818:Animals; D015220:Calcium Channels / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D008691:Methadone / Q000494:pharmacology*; D051379:Mice; D009020:Morphine / Q000494:pharmacology*; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D009294:Narcotics / Q000494:pharmacology*; D009447:Neuroblastoma; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D018408:Patch-Clamp Techniques; D014407:Tumor Cells, Cultured
D015220:Calcium Channels; D009292:Narcotic Antagonists; D009294:Narcotics; D009270:Naloxone; D009020:Morphine; D008691:Methadone