INFLUENCE OF DIETARY N-3 FATTY-ACIDS ON THE MEMBRANE-PROPERTIES OF SKELETAL-MUSCLE IN PIGS

The aim of the experiment was the ira vivo modification of long-chain fatty acids in phospholipids and to investigate the impact on Ca2+ tra nsport of sarcoplasmic reticulum (SR). Ten pigs were fed daily a diet containing 1.3 g n-3 fatty acids/kg diet (control), and ten pigs were fed a diet containing 14 g n-3 fatty acids/kg diet (n-3 diet) during t he growing-finishing period. The intake of dietary n-3 fatty acids inc reased the percentages of these fatty acids in the phospholipids of sk eletal muscle sarcoplasmic reticulum (21.6% n-3 fatty acids) and in th e polar fraction of total muscle homogenates (30.7% n-3 fatty acids) s ignificantly, compared with control (3.0% and 3.9% n-3 fatty acids, re spectively), while the n-6 fatty acid concentration was reduced. In ph osphatidylethanolamine of skeletal muscle polar lipids eicosapentnenoi c (EPA) and docosahexaenoic acids (DPA) were increased seven times com pared with control. There were no differences in the maximal rate of C a2+ uptake in skeletal muscle SR between the groups. However, the acti vity of Ca2+-ATPase of skeletal muscle SR was elevated in the n-3 diet group. It is suggested, that n-3 fatty acid enriched diet can change the complex membrane composition dependent on experimental conditions and animal species leading to different effects on membrane protein ac tivities.