Essential fatty acid deficiency: probing the role of arachidonate in biology.

EFA deficiency appears to be a uniquely useful tool in probing the role of arachidonate in a variety of physiologic and pathologic processes. Recent studies have clarified the effects of the deficiency state on tissue fatty acid content and on the production of metabolites of arachidonate and related mediators such as PAF. The ability of EFA deficiency to ameliorate a variety of inflammatory states, particularly models of autoimmune disease, is striking. The central mechanism appears to be the ability of EFA deficiency to inhibit leukocyte migration into foci of inflammation. The mechanisms underlying this phenomenon are currently under investigation. Additionally EFA deficiency has the capacity to alter dramatically tissue immunogenicity by affecting the representation of Ia-bearing cells within tissues. The role of arachidonate in the regulation of Ia-bearing cells within tissues is an area of continuing interest.