THE EFFECTS OF CYCLIC FATTY-ACID MONOMERS ON CULTURED PORCINE ENDOTHELIAL-CELLS

The popularity of polyunsaturated oils used in food applications and p reparation continues to appreciate as a result of positive health clai ms. With polyunsaturated oils inherently more susceptible to oxidative and thermal degradation, the formation of new fatty acid species incr eases considerably. The presence of one species known as cyclic fatty acid monomers (CFAM) has been detected as a component of many oils sub jected to various thermal processes including deep-fat frying. The eff ect of CFAM on metabolic processes has not been fully characterized. I n this study, confluent porcine aortic endothelial cells incorporated CFAM into their polar and nonpolar lipid fractions following a 48-h ex posure to 31 and 62 ppm CFAM in the culture medium. Subsequently, the influence of CFAM incorporation on various membrane-dependent physical properties and biochemical processes was investigated. CFAM decreased the lipid packing order of the membrane bilayer core but did not alte r the lipid packing order of lipid chain segments at or near the lipid -water interface of the membrane. CFAM led to significant reductions i n Ca2+ ATPase activity and monolayer integrity while eliciting a signi ficant increase of prostacyclin synthesis and secretion.