Dietary lipids and the inflammatory response

Inflammation is an important process in the response of the body to tissue injury and invasion by pathogens.In these contexts, the process is rapid in onset, and recedes once the pathogens are destroyed and damaged tissue has been repaired.Inflammatory and immune processes are mediated and controlled by a diverse range of molecules.Among these molecules are: proteins; the pro-inflammatory cytokines, tumour necrosis factor (TNF) and interleukins (1L)-1 and -6; derivatives from membrane phospholipids; the eicosanoids (prostaglandins (PG), leukotrienes (LT)); diacylglycerol and ceramide; miscellaneous compounds such as CAMP, inositol phosphates and reactive oxygen species.The pro-inflammatory cytokines are predominantly products of the immune system; however, endothelial cells and fibroblasts also have the capability for production.Biologically, TNF acts as a trigger which activates a cascade of cytolune production.The molecule is released rapidly in response to inflammatory and infective agents, and induces production of a large number of other cytokines, including IL-1 and IL-6 with which it shares a number of actions in common (Akira et al. 1990).These include generation of a fever, reactive oxygen species and acute-phase protein production, muscle proteolysis, hyperglycaemia, hyperlipidaemia, up-regulation of adhesion molecules and changes in the plasma concentrations of cations (Fig. 1; Tracey & Cerami, 1993;Grimble, 1996).TNF, by induction of the chemokine IL-8, may also prolong the inflammatory process (Standiford et al. 1990a,b).TNF can further modulate immunological events by induction of IL-1, whch stimulates IL-2 and IL-4 production; the latter two cytokines Hyperfriacylglyceroiaemia Fever GluconeogenesisPlasma Cu -