Influence of Thromboxane A₂ on the Regulation of Adenosine Triphosphate-Sensitive Potassium Channels in Mouse Ventricular Myocytes.
10.4070/kcj.2016.46.4.562
- Author:
In Seok JEONG
1
;
Hwa Jin CHO
;
Jeong Gwan CHO
;
Sang Hyung KIM
;
Kook Joo NA
;
Jong Keun KIM
Author Information
1. Department of Thoracic and Cardiovascular Surgery, Chonnam National University Medical School, Gwangju, Korea.
- Publication Type:Original Article
- Keywords:
KATP channels;
Thromboxane A₂;
Myocytes;
Cardiac
- MeSH:
15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid;
Adenosine Triphosphate;
Adenosine*;
Adult;
Animals;
Digestion;
Heart;
Humans;
KATP Channels;
Mice*;
Muscle Cells*;
Myocardium;
Perfusion;
Potassium Channels*;
Potassium*
- From:Korean Circulation Journal
2016;46(4):562-568
- CountryRepublic of Korea
- Language:English
-
Abstract:
BACKGROUND AND OBJECTIVES: Adenosine triphosphate (ATP)-sensitive potassium (K(ATP)) channels play an important role in myocardial protection. We examined the effects of thromboxane A₂ on the regulation of K(ATP) channel activity in single ventricular myocytes. SUBJECTS AND METHODS: Single ventricular myocytes were isolated from the hearts of adult Institute of Cancer Research (ICR) mice by enzymatic digestion. Single channel activity was recorded by excised inside-out and cell-attached patch clamp configurations at -60 mV holding potential during the perfusion of an ATP-free K-5 solution. RESULTS: In the excised inside-out patches, the thromboxane A₂ analog, U46619, decreased the K(ATP) channel activity in a dose-dependent manner; however, the thromboxane A₂ receptor antagonist, SQ29548, did not significantly attenuate the inhibitory effect of U46619. In the cell-attached patches, U46619 inhibited dinitrophenol (DNP)-induced K(ATP) channel activity in a dose-dependent manner, and SQ29548 attenuated the inhibitory effects of U46619 on DNP-induced K(ATP) channel activity. CONCLUSION: Thromboxane A₂ may inhibit K(ATP) channel activity, and may have a harmful effect on ischemic myocardium.
