08 October 2014 : Original article
Med Sci Monit Basic Res 2014; 20:153-160
BACKGROUND: It has been demonstrated that atrial electrical remodeling contributes toward atrial fibrillation (AF) maintenance, and that angiotensin II (AngII) is involved in the pathogenesis of atrial electrical remodeling. Peroxisome proliferator activated receptor-γ (PPAR-γ) agonists have been shown to inhibit atrial electrical remodeling, but the underlying mechanisms are poorly understood. In the present study we investigated the regulating effects of PPAR-g agonist on AngII-induced potassium channel remodeling in atrial myocytes.
MATERIAL AND METHODS: Whole-cell patch-clamp technique was used to record transient outward potassium current (Ito), ultra-rapid delayed rectifier potassium (Ikur), and inward rectifier potassium current (Ik1). Real-time PCR was used to assess potassium channel subunit mRNA expression.
RESULTS: Compared with the control group, AngII reduced Ito and Ikur current density as well as amplified Ik1 current density, which were partially prevented by pioglitazone. Furthermore, pioglitazone alleviated the downregulation of Ito subunit (Kv 4.2) and Ikur subunit (Kv 1.5), as well as the upregulation of Ik1 subunit (Kir 2.1 and Kir 2.2) mRNA expression stimulated by AngII.
CONCLUSIONS: These results suggest that pioglitazone exhibits a beneficial effect on AngII-induced potassium channel remodeling. PPAR-γ agonists may be potentially effective up-stream therapies for AF.
Keywords: Atrial Remodeling - drug effects, Angiotensin II - pharmacology, Cell Line, Electrophysiological Phenomena - drug effects, Gene Expression Regulation - drug effects, Heart Atria - cytology, Ion Channel Gating - drug effects, Myocytes, Cardiac - physiology, Potassium Channels - metabolism, RNA, Messenger - metabolism, Real-Time Polymerase Chain Reaction, Thiazolidinediones - pharmacology
Most Viewed Current Articles
05 Jan 2021 : Review articleA Southeast Asian Perspective on the COVID-19 Pandemic: Hemoglobin E (HbE)-Trait Confers Resistance Against...
Med Sci Monit Basic Res 2021; 27:e929207
07 Jul 2022 : Laboratory ResearchCytotoxicity, Apoptosis, Migration Inhibition, and Autophagy-Induced by Crude Ricin from Ricinus communis S...
Med Sci Monit Basic Res 2022; 28:e936683
05 May 2022 : Laboratory ResearchCalcitriol Inhibits Proliferation and Potentially Induces Apoptosis in B16-F10 Cells
Med Sci Monit Basic Res 2022; 28:e935139
09 Jun 2021 : Laboratory ResearchVitamin D Inhibits Lipopolysaccharide (LPS)-Induced Inflammation in A549 Cells by Downregulating Inflammato...
Med Sci Monit Basic Res 2021; 27:e931481