Effects of sodium azide, barium ion, d-amphetamine and procaine on inward rectifying potassium channel 6.2 expressed in Xenopus oocytes.
OBJECTIVE
Inward rectifying potassium channel 6.2 (Kir6.2DelataC26 channel) is closely related to ATP-sensitive potassium channels. Whether sodium azide, barium ion, d-amphetamine or procaine acts directly on the Kir6.2DeltaC26 channel remains unclear. We studied the effects of these compounds on Kir6.2DeltaC26 channel expressed in Xenopus oocytes.


METHODS
The coding sequence of a truncated form of mouse Kir6.2 (GenBank accession number NP_034732.1), Kir6.2(1-364) (i.e. Kir6.2DeltaC26), was subcloned into the pET20b(+) vector. Plasmid containing the correct T7 promoter-Kir6.2(1-364) cDNA fragment [Kir6.2/pET20b(+)] was then subject to NotI digestion to generate the templates for in vitro run-off transcriptions. The channel was expressed in Xenopus laevis oocytes. Two-electrode voltage clamping was used to measure the effects of sodium azide, barium ion, d-amphetamine and procaine on Kir6.2DeltaC26 channel current.


RESULTS
Sodium azide activated and barium ion and d-amphetamine inhibited the Kir6.2DeltaC26 channel. Procaine did not have any significant effect on the Kir6.2DeltaC26 channel.


CONCLUSIONS
Kir6.2DeltaC26 channel expressed in Xenopus oocytes can be used as a pharmacological tool for the study of inward rectifying potassium channels.
Kung
Fan-Lu
FL
School of Pharmacy, College of Medicine, National Taiwan University, Taipei, Taiwan.
Tsai
Jung-Lung
JL
Lee
Chien-Hsing
CH
Lou
Kuo-Long
KL
Tang
Chih-Yung
CY
Liou
Horng-Huei
HH
Lu
Kuan-Ling
KL
Chen
Yi-Hung
YH
Wang
Wun-Jheng
WJ
Tsai
Ming-Cheng
MC
D000595:Amino Acid Sequence; D000818:Animals; D001464:Barium / Q000494:pharmacology*; D001483:Base Sequence; D003913:Dextroamphetamine / Q000494:pharmacology*; D054086:KATP Channels / Q000187:drug effects; D008969:Molecular Sequence Data; D024661:Potassium Channels, Inwardly Rectifying / Q000187:drug effects*; D011343:Procaine / Q000494:pharmacology*; D011994:Recombinant Proteins / Q000187:drug effects; D019810:Sodium Azide / Q000494:pharmacology*; D014982:Xenopus laevis; D000099161:Kcnj11 Channel
D001464:Barium; D003913:Dextroamphetamine; D054086:KATP Channels; D024661:Potassium Channels, Inwardly Rectifying; D011343:Procaine; D011994:Recombinant Proteins; D019810:Sodium Azide; D000099161:Kcnj11 Channel