[Effects of opioid analgesics on potential-gated ion channels in the pond snail neurons].
The effects of opioid analgesics morphine, promedol, tramadol, and butorphanol on the transmembrane calcium, sodium, and potassium (fast and slow) ion currents in pond snail (Lymnaea stagnalis) neurons were studied by intracellular dialysis and membrane potential (voltage-clamp) measurements. It was established that all these drugs produce a dose-dependent reversible inhibition of the ion currents (sodium calcium potassium) and reduce nonspecific leak currents, thus producing a stabilizing action upon the sample membrane. The current-inhibiting effect of morphine was not eliminated by naloxone (500 microM); moreover, the latter drug significantly inhibited the ion currents as well.
Vislobokov
A I
AI
Valdman Institute of Pharmacology, Pavlov State Medical University, St. Petersburg, Russia.
Savos'kin
A L
AL
D000701:Analgesics, Opioid / Q000494:pharmacology*; D000818:Animals; D002077:Butorphanol / Q000494:pharmacology; D015220:Calcium Channels / Q000187:drug effects / Q000502:physiology; D015640:Ion Channel Gating; D007473:Ion Channels / Q000187:drug effects*; D008195:Lymnaea / Q000502:physiology*; D008564:Membrane Potentials; D015221:Potassium Channels / Q000187:drug effects / Q000502:physiology; D011396:Promedol / Q000494:pharmacology; D015222:Sodium Channels / Q000187:drug effects / Q000502:physiology; D014147:Tramadol / Q000494:pharmacology
D000701:Analgesics, Opioid; D015220:Calcium Channels; D007473:Ion Channels; D015221:Potassium Channels; D015222:Sodium Channels; D014147:Tramadol; D011396:Promedol; D002077:Butorphanol