Localization and function of ATP-sensitive potassium channels in human skeletal muscle

TY - JOUR

T1 - Localization and function of ATP-sensitive potassium channels in human skeletal muscle

AU - Nielsen, Jens Jung

AU - Kristensen, Michael

AU - Hellsten, Ylva

AU - Bangsbo, Jens

AU - Juel, Carsten

N1 - Keywords: Adenosine Triphosphate; Adult; Animals; Blotting, Western; Cell Membrane; Exercise; Glyburide; Humans; Immunohistochemistry; Ion Channel Gating; Male; Muscle, Skeletal; Potassium; Potassium Channels; Rats; Time Factors

PY - 2003

Y1 - 2003

N2 - The present study investigated the localization of ATP-sensitive K+ (KATP) channels in human skeletal muscle and the functional importance of these channels for human muscle K+ distribution at rest and during muscle activity. Membrane fractionation based on the giant vesicle technique or the sucrose-gradient technique in combination with Western blotting demonstrated that the KATP channels are mainly located in the sarcolemma. This localization was confirmed by immunohistochemical measurements. With the microdialysis technique, it was demonstrated that local application of the KATP channel inhibitor glibenclamide reduced (P < 0.05) interstitial K+ at rest from approximately 4.5 to 4.0 mM, whereas the concentration in the control leg remained constant. Glibenclamide had no effect on the interstitial K+ accumulation during knee-extensor exercise at a power output of 60 W. In contrast to in vitro conditions, the present study demonstrated that under in vivo conditions the KATP channels are active at rest and contribute to the accumulation of interstitial K+.

AB - The present study investigated the localization of ATP-sensitive K+ (KATP) channels in human skeletal muscle and the functional importance of these channels for human muscle K+ distribution at rest and during muscle activity. Membrane fractionation based on the giant vesicle technique or the sucrose-gradient technique in combination with Western blotting demonstrated that the KATP channels are mainly located in the sarcolemma. This localization was confirmed by immunohistochemical measurements. With the microdialysis technique, it was demonstrated that local application of the KATP channel inhibitor glibenclamide reduced (P < 0.05) interstitial K+ at rest from approximately 4.5 to 4.0 mM, whereas the concentration in the control leg remained constant. Glibenclamide had no effect on the interstitial K+ accumulation during knee-extensor exercise at a power output of 60 W. In contrast to in vitro conditions, the present study demonstrated that under in vivo conditions the KATP channels are active at rest and contribute to the accumulation of interstitial K+.

U2 - 10.1152/ajpregu.00303.2002

DO - 10.1152/ajpregu.00303.2002

M3 - Journal article

C2 - 12388475

SN - 0363-6119

VL - 284

SP - R558-R563

JO - American Journal of Physiology: Regulatory, Integrative and Comparative Physiology

JF - American Journal of Physiology: Regulatory, Integrative and Comparative Physiology

IS - 2

ER -