Light pollution disturbs circadian rhythm, and this can also be deleterious to the heart by increased susceptibility to arrhythmias. Herein, we investigated if rats exposed to continuous light had altered myocardial gene transcripts and/or protein expression which affects arrhythmogenesis. We then assessed if Omacor® supplementation benefitted affected rats. Male and female spontaneously hypertensive (SHR) and normotensive Wistar rats (WR) were housed under standard 12 h/12 h light/dark cycles or exposed to 6-weeks continuous 300 lux light for 24 h. Half the rats were then treated with 200 mg/100 g b.w. Omacor®. Continuous light resulted in higher male rat vulnerability to malignant ventricular fibrillation (VF). This was linked with myocardial connexin-43 (Cx43) down-regulation and deteriorated intercellular electrical coupling, due in part to increased pro-inflammatory NF-κB and iNOS transcripts and decreased sarcoplasmic reticulum Ca2+ATPase transcripts. Omacor® treatment increased the electrical threshold to induce the VF linked with amelioration of myocardial Cx43 mRNA and Cx43 protein levels and the suppression of NF-κB and iNOS. This indicates that rat exposure to continuous light results in deleterious cardiac alterations jeopardizing intercellular Cx43 channel-mediated electrical communication, thereby increasing the risk of malignant arrhythmias. The adverse effects were attenuated by treatment with Omacor®, thus supporting its potential benefit and the relevance of monitoring omega-3 index in human populations at risk.

• Keywords
• NF-κB, cardiac arrhythmias, connexin-43, iNOS, light pollution, omacor, rats,
• MeSH
• Drug Combinations MeSH
• Stress, Physiological * MeSH
• Hypertension complications   MeSH
• Connexin 43 metabolism   MeSH
• Blood Pressure drug effects   MeSH
• Rats MeSH
• Eicosapentaenoic Acid administration & dosage   chemistry   pharmacology   MeSH
• Docosahexaenoic Acids administration & dosage   chemistry   pharmacology   MeSH
• Disease Models, Animal MeSH
• Rats, Inbred SHR MeSH
• Rats, Wistar MeSH
• Dietary Supplements * MeSH
• Heart drug effects   MeSH
• Arrhythmias, Cardiac complications   physiopathology   prevention & control   MeSH
• Light Pollution * MeSH
• Aquatic Organisms MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Drug Combinations MeSH
• Connexin 43 MeSH
• Eicosapentaenoic Acid MeSH
• Docosahexaenoic Acids MeSH
• Omacor MeSH Browser