Block of Inward Rectifying K+ Channels (KIR) Inhibits Bradykinin-Induced Vasodilatation in Human Forearm Resistance Vasculature

OBJECTIVE—To investigate the possible involvement of inward rectifying K channels (KIR) in the response of human resistance vessels to bradykinin in vivo. METHODS AND RESULTS—Drugs were administered via the brachial artery in healthy male volunteers and forearm blood flow was measured by venous occlusion plethysmography. Inhibition of KIR by barium chloride (4 μmol min) alone or with additional inhibition of Na/K ATPase (ouabain 2.7 μmol min) reduced responses to bradykinin (30 pmol min), by 26±8.3% and 36±7.2%, respectively (each P