Specific alterations in different adipose tissues of pig adipocyte plasma membrane structure by dietary lipids

The effect of dietary n-6 polyunsaturated fatty acid content on pig adipocyte plasma membrane was studied with two types of adipose tissues: subcutaneous backfat layer and perirenal fat. When pigs were fed a diet containing 15 percent sunflower oil, the n-6 polyunsaturated fatty acid content in the membranes increased in both tissues parallel to a decrease in the n-9 monounsaturated fatty acid content. An increase in membrane fluidity measured by fluorescence polarization was observed particularly in subcutaneous tissue, in spite of a higher level of some membrane rigid components: the sphingomyelin/phosphatidylcholine ratio was increased in the subcutaneous tissue, whereas the cholesterol/phospholipid ratio was increased in the perirenal one. The latter results gave evidence for a depot-dependent modification in the membrane structure by dietary lipids.