Effects of paxilline on K+ channels in rat mesenteric arterial cells.
The effects of paxilline, a mycotoxin, on whole-cell outward currents from freshly isolated cells of the rat mesenteric artery were studied. Paxilline inhibited a component of the outward current that was also sensitive to iberiotoxin. Inhibition could be observed at a concentration of 10 nM and complete inhibition of the iberiotoxin-sensitive current was achieved at 300 nM. The inhibition could be described by a single site of interaction with a Ki of 35.7 nM. Paxilline had no effect on the component of the current that was sensitive to 4-aminopyridine. It is concluded that paxilline is a potent inhibitor of large conductance Ca2+ -activated K+ currents in vascular smooth muscle cells.
Li
G
G
University of Ottawa Heart Institute, Canada.
Cheung
D W
DW
D015761:4-Aminopyridine / Q000494:pharmacology; D000818:Animals; D004305:Dose-Response Relationship, Drug; D007211:Indoles / Q000494:pharmacology*; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D008638:Mesenteric Arteries / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D018408:Patch-Clamp Techniques; D010455:Peptides / Q000494:pharmacology; D015221:Potassium Channels / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar
D007211:Indoles; D010455:Peptides; D015221:Potassium Channels; C048220:paxilline; C064719:iberiotoxin; D015761:4-Aminopyridine