Recent studies on interactions between n-3 and n-6... : Current Opinion in Lipidology (original) (raw)

Lipid metabolism

Recent studies on interactions between n-3 and n-6 polyunsaturated fatty acids in brain and other tissues

aDepartment of Pediatrics, Medical University of South Carolina, Charleston, South Carolina, USA and bBrain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, Maryland, USA

Correspondence to Stanley Rapoport MD, Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Building 10, 6N-202, 9000 Rockville Pike, Bethesda, MD 20892, USA. Tel: +1 301 496 1765; fax: +1 301 402 0074; e-mail: [email protected]

Abbreviations

AA: arachidonic acid

DHA: docosahexaenoic acid

DPA: docosapentaenoic acid

PUFA: polyunsaturated fatty acid

Abstract

Recent literature provides a basis for understanding the behavioral, functional, and structural consequences of nutritional deprivation or disease-related abnormalities of n-3 polyunsaturated fatty acids. The literature suggests that these effects are mediated through competition between n-3 and n-6 polyunsaturated fatty acids at certain enzymatic steps, particularly those involving polyunsaturated fatty acid elongation and desaturation. One critical enzymatic site is a δ6-desaturase. On the other hand, an in-vivo method in rats, applied following chronic n-3 nutritional deprivation or chronic administration of lithium, indicates that the cycles of de-esterification/re-esterification of docosahexaenoic acid (22:6n-3) and arachidonic acid (20:4n-6) within brain phospholipids operate independently of each other, and thus that the enzymes regulating each of these cycles are not likely sites of n-3/n-6 competition.