[Morphine decreases the voltage sensitivity of the slow sodium channels].
Morphine was shown to decrease in a dose-dependent manner the effective charge transfer in tetrodotoxin-resistant (TTXr) sodium channel activation system in short-term cultured dorsal root ganglion cells. Morphine seems to interact with opioid receptors because of total block of the binding by naloxone and naltrexone. Neither activating, nor inhibiting G-protein agents exerted any effect on this process. The morphine signal was blocked by extracellular application of 2 x 10(-4) M ouabain. The findings suggest existence of sodium signalling pathway involving receptors, Na+, K(+)-ATPase and the TTXr sodium channels.
Krylov
B V
BV
Pavlov Institute of Physiology, Russian Academy of Sciences, St. Petersburg, Russia.
Derbenev
A V
AV
Podzorova
S A
SA
Liudyno
M I
MI
Kuz'min
A V
AV
Izvarina
N L
NL
D000818:Animals; D002462:Cell Membrane; D002478:Cells, Cultured; D005727:Ganglia, Spinal / Q000166:cytology; D009020:Morphine / Q000378:metabolism / Q000494:pharmacology*; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D018408:Patch-Clamp Techniques; D051381:Rats; D017208:Rats, Wistar; D011957:Receptors, Opioid / Q000819:agonists / Q000378:metabolism; D015222:Sodium Channels / Q000187:drug effects* / Q000502:physiology; D000254:Sodium-Potassium-Exchanging ATPase / Q000187:drug effects / Q000502:physiology; D013779:Tetrodotoxin / Q000494:pharmacology
D011957:Receptors, Opioid; D015222:Sodium Channels; D013779:Tetrodotoxin; D009020:Morphine; D000254:Sodium-Potassium-Exchanging ATPase
Morfine umen'shaet chuvstvitel'nost' k potentsialu medlennykh natrievykh kanalov.