Postnatal development of phospholipids and their fatty acid profile in rat heart

The aim of this study was to determine the concentration of phospholipids (PL), plasmalogen components of choline (PC) and ethanolamine (PE) phosphoglycerides (PLPC, PLPE) and fatty acid profile of PL and triacylglycerols (TAG) in developing rat left ventricular myocardium between postnatal day (d) 2 and 100. The steepest increase of total PL (TPL) concentration occurs between d2 and d5, followed by a further slower increase between d20 and d40. Similar developmental changes were observed in PC and PE. The PLPE concentration rises by d10, whereas PLPC does not change during the whole period investigated, except for the transient decline on d5. The concentration of diphosphatidylglycerol (DPG) increases by d60; the steepest rise occurs between d20 and d40. Phosphatidylinositol (PI) concentration rises only by d5. The concentration of phosphatidylserine (PS) decreases between d5 and d10 and then it does not change. Sphingomyelin (SM) concentration is maintained till d10, it declines on d20 and does not change thereafter. The proportion of saturated fatty acids (SFA) increases by d5 in PC, PE, PS and TAG, and by d10 in DPG and PI. After d20 the SFA proportion gradually decline in all lipids. Monounsaturated FA (MUFA) proportion decreases in PC, PE, PI and PS from d2 till d10, and in the weaning period it tends to rise again. In contrast, in DPG and TAG the proportion of MUFA declines during the whole postnatal period. N-6 polyunsaturated FA (PUFA) decrease in all PL by d20 and rise again thereafter; in TAG they decline between d2 and d10 and return to the initial level by d100. N-3 PUFA increase in all PL during the suckling period and decline after weaning; in TAG they increase only by d5 and then they decline. This remodeling of myocardial PL and TAG composition during postnatal development may affect membrane properties and contribute to developmental changes in the function of membrane proteins and cell signaling.