EPA or DHA Supplementation Increases Triacylglycerol, but not Phospholipid, Levels in Isolated Rat Cardiomyocytes

It is well recognized that a high dietary intakeof long-chain polyunsaturated fatty acids (LC-PUFA) has profound benefits on health and prevention of chronic diseases. In particular, in recent years there has beena dramatic surge of interest in the health effects of n-3LC-PUFA derived from fish, eicosapentaenoic (EPA) anddocosahexaenoic (DHA) acids. Notwithstanding, the metabolicfate and the effects of these fatty acids once insidethe cell has seldom been comprehensively investigated.Using cultured neonatal rat cardiomyocytes as model systemwe have investigated for the first time, by means ofhigh-resolution magic-angle spinning nuclear magneticresonance (HR-MAS NMR) spectroscopy in combination with gas chromatography (GC), the modification occurringin the cell lipid environment after EPA and DHA supplementation.The most important difference between controland n-3 LC-PUFA-supplemented cardiomyocytes highlightedby HR-MAS NMR spectroscopy is the increase ofsignals from mobile lipids, identified as triacylglycerols(TAG). The observed increase of mobile TAG is a metabolicresponse to n-3 LC-PUFA supplementation, whichleads to an increased lipid storage. The sequestration ofmobile lipids in lipid bodies provides a deposit of storedenergy that can be accessed in a regulated fashion according to metabolic need. Interestingly, while n-3LC-PUFA supplementation to neonatal rat cardiomyocytes causes a huge variation in the cell lipid environment, itdoes not induce detectable modifications in water-soluble metabolites, suggesting negligible interference with normal metabolic processes