Role of potassium channels in the relaxation induced by the nitric oxide (NO) donor DEA/NO in the isolated rat basilar artery.
This study investigates whether potassium ion (K+) channels are involved in the nitric oxide (NO)-induced relaxation in segments of the isolated rat basilar artery, mounted onto a wire myograph. A high extracellular K+ concentration partly inhibited the relaxant effects of the NO donors DEA/NO and SIN-1 (3-morpholino-sydnonimine). Whereas single applications of the K+ channel inhibitors tetraethyl-ammonium (10(-3) M), glibenclamide (10(-6) M), 4-aminopyridine (10(-3) M), or BaCl(2) (5 x 10(-5) M) did not affect the responses to DEA/NO, a combination of these inhibitors reduced the effects of DEA/NO. These data suggest, that the relaxant effects of NO donors are partly mediated via activation of K+channels. Different K+ channel types seem to be involved that function in a redundant manner and compensate for each other.
Hempelmann
R G
RG
Department of Neurosurgery, University of Kiel, Weimarer Strasse 8, D-24106 Kiel, Germany. hempelmannr@nch.uni-kiel.de
Seebeck
J
J
Kruse
M L
ML
Ziegler
A
A
Mehdorn
H M
HM
D015761:4-Aminopyridine / Q000494:pharmacology; D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology; D001488:Basilar Artery / Q000187:drug effects / Q000502:physiology*; D005905:Glyburide / Q000494:pharmacology; D006834:Hydrazines / Q000494:pharmacology*; D066298:In Vitro Techniques; D008297:Male; D008981:Molsidomine / Q000031:analogs & derivatives* / Q000494:pharmacology; D020030:Nitric Oxide Donors / Q000494:pharmacology*; D009589:Nitrogen Oxides; D026902:Potassium Channel Blockers / Q000494:pharmacology; D015221:Potassium Channels / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D019789:Tetraethylammonium / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology*
D000889:Anti-Arrhythmia Agents; D006834:Hydrazines; D020030:Nitric Oxide Donors; D009589:Nitrogen Oxides; D026902:Potassium Channel Blockers; D015221:Potassium Channels; C002385:linsidomine; D019789:Tetraethylammonium; C084012:1,1-diethyl-2-hydroxy-2-nitrosohydrazine; D015761:4-Aminopyridine; D008981:Molsidomine; D005905:Glyburide