Fatty Acid Synthesis in vitro in a System from Rat Liven ∗

Summary

A preparation from rat liver containing both microsomes and soluble enzymes when supplemented with the necessary cofactors incorporates acetate-1-¹⁴C preponderantly into the saponiflable fraction of the lipids. Bicarbonate has no significant stimulating effect on the synthesis whereas citrate and malonate have pronounced and similar stimulatory effects, particularly when they are preincubated with the synthesizing system. However, at high citrate concentrations bicarbonate becomes inhibitory, Malonate stimulates fatty acid synthesis without participating as a metabolite. The same is concluded with citrate, at least with concentration up to 15 mM. An interrelationship between citrate and ATP concentrations and the stimulation of fatty acid synthesis is indicated.