Effects of a high linoleic acid diet on the fatty acid composition of leucocytes from Atlantic salmon (Salmo salar).

Mammalian cells can metabolize linoleic acid (C,8:2, , , , , ) by A-6-desaturation to y-linoleic acid (C18:3,,,-,,), which can be elongated to dihomo-y-linoleic acid (C211.3,,z, ), and subsequently undergo A-5-desaturation to arachidonic acid (AA) (C211:J,rr-,,) 11 I . Most freshwater fish are also capable o f this process 121, whereas marine species such as turbot (Scopthulmirs maximus) apparently lack A-5-desaturase and thus require the highly unsaturated fatty acids (HUFA), eicosapentaenoic acid (EPA), ( C20:5,,, 3 ) , docosahexaenoic acid (C,: , , ,,> ) and probably C,o:J,,,-,~ to be supplied by the diet [ 31. Studies with Atlantic salmon undergoing smoltification indicated an inability to elongate and desaturate CIS,:,,, .,, [4], although post-smolts given corn-oil-containing diets showed increased C21,,,,f-,, in liver and muscle lipids