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.
Inomoto
C
C
Department of Physiology, Tokai University School of Medicine, Isehara, Kanagawa, Japan.
Tokimasa
T
T
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