Influence of Vasoactive Substances on the Regulation of Cardiac ATP-Sensitive Potassium Channel Activity.
10.4070/kcj.2006.36.7.516
- Author:
Jae Ha KIM
1
;
Jeong Min JU
;
Ling Hua PIAO
;
Yun Yee KIM
;
Han Seong JEONG
;
Hyung Wook PARK
;
Dae Ho JEONG
;
Sang Rok LEE
;
Nam Sik YOON
;
Kye Hun KIM
;
Young Joon HONG
;
Ju Han KIM
;
Weon KIM
;
Young Keun AHN
;
Myung Ho JEONG
;
Jeong Gwan CHO
;
Jong Chun PARK
;
Jung Chaee KANG
Author Information
1. Department of Pharmacology, Chonnam National University Medical School, Gwangju, Korea.
- Publication Type:Original Article
- Keywords:
ATP;
Potassium channels;
Vasoconstrictors;
Vasodilators
- MeSH:
Adenosine Triphosphate;
Animals;
Bradykinin;
Digestion;
Endothelins;
Epoprostenol;
Glyburide;
Heart;
Leukotriene D4;
Mice;
Mice, Inbred ICR;
Muscle Cells;
Myocytes, Cardiac;
Potassium Channels*;
Potassium*;
Vasoconstrictor Agents;
Vasodilator Agents
- From:Korean Circulation Journal
2006;36(7):516-525
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
BACKGROUND AND OBJECTIVES: It has been known that various vasoactive agents are involved in the regulation of cardiac function through the modification of the K+ channel activities, including the ATP-sensitive K+ channel (KATP). We examined the effects of several vasoactive agents on the cardiac KATP currents in isolated cardiac myocytes. MATERIALS AND METHODS: Ventricular myocytes were isolated from the hearts of ICR mice by enzymatic digestion. The channel currents were recorded by the excised inside-out and cell-attached patch clamp configurations. RESULTS: In the excised inside-out patches, bradykinin (BRK; 1-10 micrometer) and prostaglandin I2 (PGI; 10-50 micrometer) did not affect the channel activities, whereas the vasodilators increased the attenuated channel activities in the presence of 100 micrometer ATP. BRK and PGI in parallel shifted the dose-response curves of ATP (1-1,000 micrometer), and this inhibited the KATP currents to the right. Endothelin (ET-1; 0.1-1 nM) and leukotriene D4 (LTD; 3-10 micrometer) decreased the channel activities immediately after making the inside-out patches. However, the vasoconstrictors did not affect the attenuated channel activities by ATP. In the cell-attached patches, both BRK and PGI increased the channel activities and these effects were markedly attenuated by glibenclamide (50 micrometer). ET-1 and LTD did not affect the baseline channel activities in the cell-attached patches, but they markedly attenuated the dinitrophenol-induced activities. CONCLUSION: It was inferred that certain vasoactive substances are involved in the regulation of cardiac KATP channel activities, and that bradykinin and PGI2 enhance the channel activities, and ET-1 and LTD4 inhibit the channel activities.
