EFFECTS OF POLYUNSATURATED FATTY-ACIDS ON THE IMMUNE-SYSTEM - THEIR SIGNIFICANCE AS COMPONENTS OF MEMBRANE STRUCTURES AND MEDIATORS

Objective: A review of pharmacodynamic effects induced by polyunsatura ted fatty acids (PUFA) with special emphasis on their significance as components of biomembranes and as precursors for mediator formation. D ata sources: Original papers as well as review articles in German and English were retrieved by repeated MEDLINE research. Selection criteri a: Pertinent original papers as well as review articles since 1983 as well as some significant original papers of earlier origin were used. Results: The current classification of different groups of fatty acids , due to their degree of desaturation, implies that various classes of fatty acids can be correlated to either energetic or structural or fu nctional tasks, respectively. PUFAs are an integral part of membrane s tructures and serve as precursors of mediator synthesis. They are ther efore prone to have major impact on cell function. In particular, inte ractions between PUFAs and the immune system are substantially determi ned by the effects of different eicosanoids, which are also derived fr om PUFAs. However, their impact on various immune functions is dose de pendent as well as quantitatively different. If the immune response me diated by eicosanoids is under consideration, actions on the specific immune system have to be discriminated from effects on nonspecific imm unity. Conclusion: During homeostasis, PUFAs as well as their derived mediators are important factors for a well-operating immune system. If , however, eicosanoid synthesis becomes either diminished or augmented , functions related to the specific immune response are impaired. By c ontrast, the intensity of the nonspecific immune response is strongly related to the amount of mediators released. During nutritional therap y, lipids not only provide an energetic source but also interfere with structural integrity and functional performance of the cell.