Selective incorporation of various C-22 polyunsaturated fatty acids in Ehrlich ascites tumor cells

Journal Article · Sat Nov 01 04:00:00 EST 1986 · J. Lipid Res.; (United States)

OSTI ID:6791359

Masuzawa, Y; Okano, S; Waku, K; Sprecher, H; Lands, W E

Three /sup 14/C-labeled 22-carbon polyunsaturated fatty acids, 7,10,13,16-(/sup 14/C)docosatetraenoic acid (22:4(n-6)), 7,10,13,16,19-(/sup 14/C)docosapentaenoic acid (22:5(n-3)), and 4,7,10,13,16,19-(/sup 14/C)docosahexaenoic acid (22:6(n-3)), were compared with (/sup 3/H)arachidonic acid (20:4(n-6) and (14C)linoleic acid (18:2(n-6)) to characterize their incorporation into the lipids of Ehrlich ascites cells. The relatively rapid incorporation of the labeled 22-carbon acids into phosphatidic acid indicated that substantial amounts of these acids may be incorporated through the de novo pathway of phospholipid synthesis. In marked contrast to 20:4(n-6), the 22-carbon acids were incorporated much less into choline glycerophospholipids (CGP) and inositol glycerophospholipids (IGP). No selective preference was apparent for the (n-3) or (n-6) type of fatty acids. The amounts of the acids incorporated into diacylglycerophosphoethanolamine were in the order of: 22:6(n-3) greater than 20:4(n-6) much greater than 22:5(n-3) greater than or equal to 22:4(n-6) greater than 18:2(n-6), whereas for alkylacylglycerophosphoethanolamine they were in the order of: 22:4(n-6) greater than 22:6(n-3) greater than 22:5(n-3) much greater than 20:4(n-6) greater than 18:2(n-6). Of the mechanisms possibly responsible for the selective entry of 22-carbon acids into ethanolamine glycerophospholipids, the most reasonable explanation was that the cytidine-mediated ethanolamine phosphotransferase may have a unique double selectivity: for hexaenoic species of diacylglycerol and for 22-carbon polyunsaturated fatty acid-containing species of alkylacylglycerol. The relative distribution of fatty acids between newly incorporated and already maintained lipid classes suggested that IGP may function in Ehrlich cells as an intermediate pool for the retention of polyunsaturated fatty acids in glycerolipids.

• Research Organization: Teikyo Univ., Kanagawa, Japan
• OSTI ID: 6791359
• Journal Information: J. Lipid Res.; (United States), Journal Name: J. Lipid Res.; (United States) Vol. 11; ISSN JLPRA
• Country of Publication: United States
• Language: English

Related Subjects

550501* -- Metabolism-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMAL CELLS
ANIMALS
CARBON 14 COMPOUNDS
CARBOXYLIC ACIDS
EHRLICH ASCITES TUMOR
ESTERS
EXPERIMENTAL NEOPLASMS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LIPIDS
MAMMALS
METABOLISM
MICE
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
PHOSPHOLIPIDS
RODENTS
STRUCTURE-ACTIVITY RELATIONSHIPS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
TUMOR CELLS
VERTEBRATES