Effects of meconic and comenic acids on slow sodium channels of secondary neurons.
Effects of comenic and meconic acids on cultured dorsal root ganglion cells were investigated by the whole-cell patch clamp technique. The acids, having a well-known antiinflammatory and antibacterial action, decreased effective charge transfer in the activation gating system of TTX-resistant (slow) sodium channels in a dose-dependent manner. The effects were described by Hill's equation. The dissociation constant and Hill coefficient values were K(D) = 100 nM and X = 0.5 (for comenic acid) and K(D) = 10 nM and X = 0.34 (for meconic acid). The nonspecific antagonist of opioid receptors naltrexone totally blocked the effects. We suggest that the acids studied activate a subpopulation of opioid receptors negatively coupled to TTXr sodium channels.
Derbenev
A V
AV
Pavlov Institute of Physiology, Russian Academy of Sciences, St. Petersburg.
Krylov
B V
BV
Shurygin AYa
D000818:Animals; D018929:Cell Culture Techniques; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D005727:Ganglia, Spinal / Q000187:drug effects / Q000378:metabolism; D007700:Kinetics; D009020:Morphine / Q000378:metabolism / Q000494:pharmacology; D009475:Neurons, Afferent / Q000187:drug effects* / Q000378:metabolism*; D011753:Pyrones / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D015222:Sodium Channels / Q000187:drug effects* / Q000378:metabolism*; D013997:Time Factors
D011753:Pyrones; D015222:Sodium Channels; D009020:Morphine; C010603:meconic acid