The role of delta-6- and delta-9-desaturase in the fatty acid metabolism of hepatomas with different growth rate.

The fatty acid composition of microsomal membranes from Morris hepatomas 9618A, slow growing, and 3924A, fast growing, confirm the higher content in oleic acid and the loss of PUFAs of the tumours with respect to controls. The specific activities of delta-9-desaturase indicate alternative metabolic pathways for the increased production of oleic acid in the two hepatomas. The delta-6-desaturase activity is much lower in tumours than in controls. However the loss of PUFAs found in tumours seems to be mostly due to a low content in linoleic acid.