Polyunsaturated Fatty Acids Flashcards
Two main functions of PUFA?
Facilitative (palatability/texture, dense calorie source, energy, fat soluble vitamin absorption)
Functional ( cell regulation and or metabolism)
Fatty acid nomenclature is based on
Position of the first double bond
Linoleic Acid
Found in phospholipid ceramidies
Extruded from epidermal keratinocytes as intracellular lamellar granules
Enhances cell adhesion and impart an effective water barrier to the epidermis
Alpha Linolenic Acid
+/- contribution to the effective transepidermal water barrier
Provides a sparing effect of linolenic acid
Increased linolenic acid accumulation in ceramide fractions of the skin
Arachidonic Acid
20-25% of total FA of cell membrane phospholipids of the skin and other tissues
Hepatic Synthesis and transported via circulating lipoproteins
Eicosapentaenoic Acid
Competitive substitute for arachidonic acid
Hyperbolic, non-linear relationship
Clinical signs of essential fatty acid deficiency
Poor growth and weight gain, cutaneous changes, infertility and poor wound healing
Eicosanoids
20 carbon, oxygenated atoms
Synthesized locally on demand by individual cell types in response to their immediate environment
Cyclooxygenase (COX) products
Eicosanoid
Prostaglandins (vasodilators) and thromboxaines
Lipoxygenase (LO) products
Eicosanoid
Leukotrienes (vasoconstrictors) - stimulate chemotaxis and thromboxane release
N (3/6) are more effective in inhibiting n (3/6) PUFA metabolism than vice versa
N-3 ; N-6
Immune reactivity is generally reduced by n (3/6) PUFA
N-3
Biological effects of N-3 PUFA are mediated, in part, through changes in
Eicosanoid production
Eicosanoids regulate production and biologic function of
Cytokines
