Effect of chronic wheel running on the fatty acid composition of phospholipids and triacylglycerols in rat serum, skeletal muscle and heart

Aim: The purpose of this study was to examine the effects of long-term wheel running on the fatty acid composition of phospholipids (PL) and triacylglycerols (TG) in rat serum, skeletal muscle (soleus and extensor digitorum longus) and heart. Methods: To this end, the relevant tissues of 11 trained male Wistar rats were compared with those of 14 untrained ones. Results: There were several significant differences between the two groups regarding the concentrations and percentages of individual fatty acids in serum PL and TG, with most differences appearing in the fatty acid distribution of PL. Monounsaturated fatty acids of muscle PL were significantly lower in the trained rats. Estimated elongase activity was significantly higher, whereas Δ⁹-desaturase activity was significantly lower in the trained muscles. Monounsaturated fatty acids of PL were also significantly lower in the trained hearts. The fatty acid composition of PL in the skeletal muscles and the heart adapted to training in a comparable manner, whereas most of the changes in the fatty acid profile of TG were tissue-dependent. Judging from the magnitude of the effect sizes and the percentage differences between trained and untrained animals, there were many large effects of chronic exercise on the fatty acid composition of the tissues examined. Conclusion: Long-term wheel running modified the fatty acid profile of PL and TG in rat serum, skeletal muscle and heart, and could thus be considered as a modulator of tissue fatty acid composition.