Regulation of voltage-gated K+ channels by glucose metabolism in pancreatic beta-cells.
Regulation of delayed rectifier-type K(+) channels (Kv-channels) by glucose was studied in rat pancreatic beta-cells. The Kv-channel current was increased in amplitudes by increasing glucose concentration from 2.8 to 16.6mM, while it was decreased by 2.8mM glucose in a reversible manner (down-regulation) in both perforated and conventional whole-cell modes. The current was decreased by FCCP, intrapipette 0mM ATP or AMPPNP. Glyceraldehyde, pyruvic acid, 2-ketoisocaproic acid, and 10mM MgATP prevented the down-regulation induced by 2.8mM or less glucose. The residual current after treatment with Kv2.1-specific blocker, guangxitoxin-1E, was unchanged by lowering or increasing glucose concentration. We conclude that glucose metabolism regulates Kv2.1 channels in rats beta-cells via altering MgATP levels.
Yoshida
Masashi
M
First Department of Medicine, Saitama Medical Center, Jichi Medical University School of Medicine, Omiya 1-847, Saitama, Japan.
Dezaki
Katsuya
K
Yamato
Shiho
S
Aoki
Atsushi
A
Sugawara
Hitoshi
H
Toyoshima
Hideo
H
Ishikawa
San-e
SE
Kawakami
Masanobu
M
Nakata
Masanori
M
Yada
Toshihiko
T
Kakei
Masafumi
M
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D015536:Down-Regulation; D005947:Glucose / Q000378:metabolism*; D050417:Insulin-Secreting Cells / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D018408:Patch-Clamp Techniques; D024642:Potassium Channels, Voltage-Gated / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013696:Temperature
D024642:Potassium Channels, Voltage-Gated; D000255:Adenosine Triphosphate; D005947:Glucose