Effects of barium on delayed rectifier potassium current in bullfrog sympathetic neurons pretreated with wortmannin.
The effect of barium (1 mM) on a delayed rectifier-type potassium current was examined in bullfrog sympathetic neurons. An M-type potassium current was eliminated by pretreatment of the cells with a microbial product, wortmannin (10 microM). An A-type potassium current was continuously inactivated by setting a holding potential at -65 mV. In treated cells (n = 10), the delayed rectifier at 0 mV averaged 2200 +/- 107 pA in the presence of barium (1 mM) as compared to 2308 +/- 110 pA in the controls, and 2085 +/- 103 pA after washing out the barium. It is concluded that the delayed rectifier is insensitive to barium blockage in amphibian autonomic neurons.
Department of Physiology, Tokai University School of Medicine, Isehara, Kanagawa, Japan.
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Inomoto
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Tokimasa
D000730:Androstadienes / Q000494:pharmacology*; D000818:Animals; D001464:Barium / Q000494:pharmacology*; D002478:Cells, Cultured; D051668:Delayed Rectifier Potassium Channels; D005728:Ganglia, Sympathetic / Q000187:drug effects* / Q000502:physiology; D026902:Potassium Channel Blockers; D015221:Potassium Channels / Q000187:drug effects* / Q000502:physiology; D024642:Potassium Channels, Voltage-Gated; D011892:Rana catesbeiana; D000077191:Wortmannin
D000730:Androstadienes; D051668:Delayed Rectifier Potassium Channels; D026902:Potassium Channel Blockers; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated; D001464:Barium; D000077191:Wortmannin