Activation of the Cardiac ATP-Sensitive K+Channel by KR-30816,Newly Synthesized Potassium Channel Opener
Korean Circulation Journal
;
: 889-898, 1994.
Article
in Korean
| WPRIM
| ID: wpr-206730
ABSTRACT
BACKGROUND:
The effects of a newly synthesized potassium channel opener, KR-30816((-)(nitro-2-hydroxymethyl-2-methy-2H-1-benzopyran-4-y1)pyridine oxide) on the action potential of papillary muscles of guinea pigs and the ATP-sensitive potassium channel current(IKATP) of single ventricular muscle cells of rats were examined to make clear its action mechanism of the KATPchannel.METHODS:
We used the conventional microelectrode and the excised inside-out patch configuration.RESULTS:
KR-30816 caused a shortening of the action potential duration in dose-dependent manner, which was inhibited by glibenclamide(3microM). Before run-down of the K+channel, KR-30816 activated the cardiac ATP-sensitive K+ channel only in the presence of ATP and shifted the dose-response relation curve between [ATP]i and the channel activity to the right in parallel. After run-down of the KATP channel, KR-30816 did not after the channel opening either in the absence or in the presence of UDP.CONCLUSION:
These results suggest that KR-30816 antagonizes the inhibitory effect of ATP on the KATPchannel in a competitive manner, thereby enhancing the channel openings.
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Papillary Muscles
/
Potassium
/
Uridine Diphosphate
/
Action Potentials
/
Potassium Channels
/
Adenosine Triphosphate
/
Muscle Cells
/
Guinea Pigs
/
Heart
/
Microelectrodes
Type of study:
Diagnostic study
Limits:
Animals
Language:
Korean
Journal:
Korean Circulation Journal
Year:
1994
Type:
Article
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