Effects of Endothelium-derived Relaxing Factors on the Regulation of ATP-sensitive Potassium Channel Activity in Cardiac Myocytes
Korean Circulation Journal
;
: 420-430, 2003.
Article
in Korean
| WPRIM
| ID: wpr-49601
ABSTRACT
BACKGROUND AND OBJECTIVES:
Effects of the three major endothelium-derived relaxing factors (EDRFs), namely nitric oxide (NO), prostacyclin (PGI2), and 11, 12-epoxyeicosatrienoic acid (EET) on the ATP-sensitive potassium channel (K ATP channel) activity were examined in isolated cardiac ventricular myocytes. MATERIALS ANDMETHODS:
K ATP channel activities were measured in the enzymatically (collagenase) isolated single mouse ventricular myocytes using excised inside-out, cell-attached, and perforated whole-cell patch clamp techniques.RESULTS:
In inside-out patches, NO donors, SNP and spermine NONOate, did not affect the K ATP channel activity. In the presence of both ATP and ADP in the bath solution, the NO donors attenuated the activity of the K ATP channel. In cell-attached patches, the NO donors potentiated pinacidil-induced K ATP channel activity. In perforated whole-cell patch configuration, the NO donors decreased the K ATP current induced by PCO 400, a K ATP channel opener. PGI2 did not affect the K ATP channel activity in excised insideout patch. However, in the pres-ence of ATP in the internal solution, PGI2 increased the channel activity in a dose-dependent manner. In cell-attached patches, PGI2 did not only affect the channel activity itself, but also the dinitrophenol-induced K ATP channel activity. 11, 12-EET had no effect on K ATP channel activities.CONCLUSION:
These results indicate that some of the endothelium-derived relaxing factors (nitric oxide and prostacyclin) are involved in the regulation of ATP-sensitive potassium channel activities in mouse ventricular myocytes; and the regulation type was com-plicated, activation or inhibition, depending on the cellular environment.
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Potassium
/
Tissue Donors
/
Baths
/
Potassium Channels
/
Spermine
/
Adenosine Diphosphate
/
Adenosine Triphosphate
/
Epoprostenol
/
Patch-Clamp Techniques
/
Muscle Cells
Type of study:
Diagnostic study
Limits:
Animals
/
Humans
Language:
Korean
Journal:
Korean Circulation Journal
Year:
2003
Type:
Article
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