Relationship between desaturation and chain elongation of palmityl-CoA in rat liver microsomes

The relationship between desaturation and chain elongation of palmityl-CoA was studied in rat liver microsomes. Enzyme activities for desaturation and chain elongation were stimulated by re-feeding starved rats. The activities of desaturation and chain elongation in re-fed rats were four- and twofold greater than those in normal rats, respectively. When a sonicated dispersion of lecithin was added to the incubation medium containing both reactions, chain elongation activity, especially formation of stearic acid, was stimulated and desaturation activity was apparently depressed.