Elongation of 20-carbon polyunsaturated fatty acids by human skin fibroblasts

Conference · Thu May 01 04:00:00 EDT 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:5277862

Banerjee, N; Rosenthal, M D

Human skin fibroblasts readily incorporate exogenous arachidonate (20:4(n-6)) and eicosapentaenoate (20:5(n-3)) into cellular phospholipids and triacylglycerol. The extent of incorporation of 1.25 ..mu..M (/sup 14/C)20:4(n-6) and (/sup 14/C)20:5(n-3) from culture medium with delipidized serum protein is similar, 20% in 1 hr increasing to 60-70% within 8 hr. Elongation of incorporated (/sup 14/C)20:5(n-3) to (/sup 14/C)22:5(n-3) is extensive, 40% by 8 hr and 85% by 48 hr. Elongation of (/sup 14/C)20:4(n-6) to (/sup 14/C)22:4(n-6) is <1/2 that of (/sup 1/$C)20:5(n-3) and plateaus at approx.20% of incorporated /sup 14/C-fatty acid. Although incorporated, exogenous 22:4(n-6) is not an effective inhibitor of the elongation of (/sup 14/C)arachidonate; however, exogenous 20:5(n-3) is inhibitory, with an ID/sub 50/ of 5 ..mu..M. With exogenous concentrations of (/sup 14/C)arachidonate from 0.4 - 10 ..mu..M, the percentage incorporated in 24 hr remains relatively constant. By contrast, the extent of elongation of incorporated (/sup 14/C)arachidonate increases from 12% at 0.4 ..mu..M to 43% at 10 ..mu..M. Under these conditions, elongation of incorporated (/sup 14/C)20:5(n-3) is approx.75%. Thus, in these cells, selectivity of the elongation system results in differential metabolism of 20-carbon n-6 and n-3 fatty acids. Furthermore, arachidonate appears to act as a positive modulator of its own elongation.

• Research Organization: Eastern Virginia Medical School, Norfolk
• OSTI ID: 5277862
• Report Number(s): CONF-8606151-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 45:6
• Country of Publication: United States
• Language: English

Related Subjects

550501* -- Metabolism-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMAL CELLS
ANIMALS
ARACHIDONIC ACID
BODY
CARBON 14 COMPOUNDS
CARBOXYLIC ACIDS
CONNECTIVE TISSUE CELLS
EICOSANOIC ACID
FIBROBLASTS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MAMMALS
MAN
METABOLISM
MONOCARBOXYLIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
PRIMATES
SKIN
SOMATIC CELLS
TRACER TECHNIQUES
VERTEBRATES