Effects of dietary eritadenine on delta6-desaturase activity and fatty acid profiles of several lipids in rats fed different fats.

Effects of dietary eritadenine on liver microsomal delta6-desaturase activity and the fatty acid profile of phosphatidylcholine, cholesteryl esters, and triglycerides of liver microsomes or plasma were investigated in rats fed different fats (palm oil, olive oil, and safflower oil). The activity of delta6-desaturase was influenced by both dietary fat types and eritadenine. In rats fed control diets, delta6-desaturase activity was higher in the order of the palm oil, olive oil, and safflower oil groups. In rats fed eritadenine-supplemented diets, the enzyme activity was markedly decreased to a constant level irrespective of dietary fat type. The 20:4n-6/18:2n-6 ratio of phosphatidylcholine and cholesteryl esters, as compared with triglycerides, was highly sensitive to eritadenine. The results suggest that the activity of delta6-desaturase is regulated by dietary fats and eritadenine independently, and that the effect of eritadenine is stronger than that of dietary fats.