Effect of a high linoleic acid diet on delta 9-desaturase activity, lipogenesis and lipid composition of pig subcutaneous adipose tissue.

The effects of three diets were compared: a high linoleic acid diet (diet M containing 4% maize oil), diet T containing 4% beef tallow, and C, a conventional control diet, on delta 9-desaturase activity and lipogenesis in pig subcutaneous adipose tissue. Diet M increased lipogenesis (estimated from the activities of acetyl-CoA-carboxylase, malic enzyme and glucose-6-phosphate dehydrogenase), and decreased delta 9-desaturase activity, in comparison to the other diets. Linoleic acid content was higher in the pigs fed diet M than in the other pigs (amounting to 26% of total tissue fatty acids versus 15%, respectively). The lower monounsaturated fatty acid content in adipose tissue of pigs fed diet M compared to pigs fed other diets could be associated with the lower delta 9-desaturase activity and the lower oleic acid content of diet M. The present study suggests that delta 9-desaturase could be involved in the regulation of monounsaturated fatty acid content and hence in the quality of pig adipose tissue.