Up-regulation of myocardial connexin-43 in spontaneously hypertensive rats fed red palm oil is most likely implicated in its anti-arrhythmic effects

• Published in: Canadian journal of physiology and pharmacology 2012-09, Vol.90 (9), p.1235-1245
• Main Authors: BACOVA, Barbara, RADOSINSKA, Jana, SLEZAK, Jan, TRIBULOVA, Narcis, VICZENCZOVA, Csilla, KNEZL, Vladimir, DOSENKO, Victor, BENOVA, Tamara, NAVAROVA, Jana, GONCALVESOVA, Eva, ROOYEN, Jacques Van, WEISMANN, Peter
• Format: Article
• Language: English
• Subjects: Animals; Anti-Arrhythmia Agents - administration & dosage; Anti-Arrhythmia Agents - pharmacology; Anti-Arrhythmia Agents - therapeutic use; Anti-arrhythmia drugs; arrhythmias; Arrhythmias, Cardiac - etiology; Arrhythmias, Cardiac - metabolism; Arrhythmias, Cardiac - prevention & control; arythmie; Biological and medical sciences; Blood Pressure - physiology; Blotting, Western; Cardiac arrhythmia; Connexin 43 - biosynthesis; connexin-43; connexine-43; cœur; Development and progression; Fundamental and applied biological sciences. Psychology; Health aspects; Heart; Heart muscle; huile de palme rouge; Hypertension; Hypertension - complications; Hypertension - drug therapy; Hypertension - enzymology; Hypertension - metabolism; In Vitro Techniques; Male; Myocardium - enzymology; Myocardium - metabolism; Palm Oil; Physiological aspects; PKC; PKCε; Plant Oils - administration & dosage; Plant Oils - pharmacology; Plant Oils - therapeutic use; Proteins; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Real-Time Polymerase Chain Reaction; red palm oil; Rodents; SHR; Up-Regulation; Vegetable oils; Vertebrates: anatomy and physiology, studies on body, several organs or systems
• ISSN: 0008-4212; 1205-7541
• DOI: 10.1139/y2012-103

The purpose of this study was to test our hypothesis that red palm oil (RPO) intake may affect abnormalities of myocardial connexin-43 (Cx43) and protein kinase Cε (PKCε) signaling, and consequently the propensity of the spontaneously hypertensive rat heart (SHR) heart to arrhythmias. SHR and Wistar–Kyoto (WKY) rats fed a standard rat chow plus red palm oil (200 µL/day) for 5 weeks were compared with untreated rats. Cytosolic but not particulate PKCε expression as well as Cx43-mRNA, total Cx43 proteins, and its phoshorylated forms were increased, and disordered localization of Cx43 was attenuated in the left ventricle of RPO-fed SHR compared with untreated rats. These alterations were associated with suppression of early post-ischemic-reperfusion-related ventricular tachycardia and electrically inducible ventricular fibrillation. However, the treatment dose of RPO caused down-regulation of myocardial Cx43, but did not alter its cell membrane distribution or overall PKCε expression in WKY rats. It was, however, associated with poor arrhythmia protection, suggesting overdosing. Results indicate that SHR benefit from RPO intake, particularly because of its apparent anti-arrhythmic effects. This protection can be, in part, attributed to the preservation of cell-to-cell communication via up-regulation of myocardial Cx43, but not with PKCε activation.