Nitric oxide activates an iberiotoxin-sensitive potassium channel in human saphenous vein.
Synthetic iberiotoxin (IBTX), an inhibitor of large conductance calcium-activated potassium channel (BKCa), was used to study the possible involvement of a specific hyperpolarizing ion channel in nitric oxide (NO)-induced venodilation. Serotonin (0.125 microM)-induced contraction of isolated human saphenous vein was dose-dependently relaxed with 50-1550 nanoM exogenous NO. 30 min preincubation of venous preparations with 90 nanoM IBTX decreased vasorelaxation induced by NO. In conclusion, a hyperpolarizing potassium channel, BKCa, may be involved in the venodilator effect of endogenous NO.
Höhn
J
J
Department of Surgery, Albert Szent-Györgyi Medical University, Szeged, Hungary.
Pataricza
J
J
Tóth
G K
GK
Balogh
A
A
Papp
J G
JG
D004305:Dose-Response Relationship, Drug; D006801:Humans; D066298:In Vitro Techniques; D009569:Nitric Oxide / Q000494:pharmacology*; D010455:Peptides / Q000494:pharmacology*; D015221:Potassium Channels / Q000187:drug effects* / Q000378:metabolism*; D012501:Saphenous Vein / Q000378:metabolism*; D012701:Serotonin / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects
D010455:Peptides; D015221:Potassium Channels; D009569:Nitric Oxide; D012701:Serotonin; C064719:iberiotoxin