Essential fatty acid deficiency: a new look at an old problem.

Essential fatty acid (EFA) deficiency is a useful tool to study the role of arachidonate and its metabolites in various physiologic and pathologic states. Recent studies have clarified the effects of EFA deficiency on membrane arachidonate and its metabolites, and have demonstrated that 20:3(n-9) (which accumulates in EFA deficiency) can be metabolized to a variety of eicosanoids. EFA deficiency has been shown to exert an anti-inflammatory effect. The mechanism of this effect may in part be mediated through a decrease in leukocyte leukotriene formation. In contrast, studies using the novel fatty acid, columbinic acid, have shown that the epidermal dysfunction seen in EFA deficiency may be a function of linoleate and its lipoxygenase metabolites rather than of arachidonate and the prostaglandins. Finally, it has recently been shown that EFA deficiency potentiates the effects of volatile anesthetics. EFA deficiency may thus provide a useful tool to investigate the molecular mechanism of these drugs.