Inhibition of serotonin uptake into mouse brain synaptosomes by ionophores and ion-channel agents.
[3H]Serotonin uptake into mouse cerebrocortical synaptosomes was decreased by the K+ ionophore valinomycin, the K+ and Na+ ionophore gramicidin, and the proton ionophore carbonylcyanide m-chlorophenylhydrazone. The Na+/H+ exchanger monensin reduced uptake at non-depolarizing concentrations. Uptake was also decreased by inhibition of the Na+, K(+)-ATPase with ouabain and by tetrodotoxin-sensitive activation of voltage-dependent sodium channels with veratridine, batrachotoxin and scorpion venom. In contrast, the Ca2+ channel agents BAY K8644 and nimodipine were ineffective. The effect of reducing the Na+ gradient depended upon whether the internal Na+ concentration was raised (i.e. by scorpion venom, monensin) or the external Na+ concentration was lowered (37 mM NaCl in the medium).
Reith
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Center for Neurochemistry, Nathan S. Kline Institute for Psychiatric Research New York, NY 10035.
O'Reilly
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D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism*; D006096:Gramicidin / Q000494:pharmacology*; D007473:Ion Channels / Q000187:drug effects / Q000502:physiology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008985:Monensin / Q000494:pharmacology*; D015221:Potassium Channels / Q000187:drug effects / Q000502:physiology; D012701:Serotonin / Q000493:pharmacokinetics*; D015222:Sodium Channels / Q000187:drug effects / Q000502:physiology; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism*; D014634:Valinomycin / Q000494:pharmacology*
D007473:Ion Channels; D015221:Potassium Channels; D015222:Sodium Channels; D006096:Gramicidin; D014634:Valinomycin; D012701:Serotonin; D008985:Monensin