Fatty Acid and 3-β-Hydroxysterol Synthesis in the Perfused Rat Liver

Conditions are described for perfusing rat livers in vitro which result in rates of fatty acid synthesis which equal the rates observed in vivo. Rates of 3-β-hydroxysterol synthesis by the perfused liver are equal to or greater than those observed in vivo. Livers from starved animals perfused with low concentrations of glucose show low rates of fatty acid and 3-β-hydroxysterol synthesis. When such livers are perfused with high concentrations of glucose they show a substantial increase in the rate of fatty acid and 3-β-hydroxysterol synthesis. These increases are compared with similar increases in vivo, which are observed when starved animals are refed. Relationships are examined between rates of fatty acid synthesis and the production of lactate, pyruvate, β-hydroxybutyrate, and acetoacetate, as well as the oxygen consumption. Metabolite contents are reported for perfused livers that exhibit high and low rates of fatty acid synthesis.