Interaction of propionate and lactate in the perfused rat liver. Effects of glucagon and oleate.

The uptake of propionate by the isolated perfused rat liver is not influenced by oleate or glucagon. However, glucagon does stimulate glucose production in the presence of 10 flwl propionate and increases the incorporation of isotope from [14C]propionate into glucose. These observations have been interpreted to indicate a sparing of the metabolism of propionate in the citric acid cycle by endogenous materials. As others have noted, propionate inhibits gluconeogenesis from lactate in the perfused liver. Studies of the influence of glucagon and oleate on glucose production from a mixture of propionate and lactate suggest that glucagon is acting at some point in common with the metabolism of propionate and lactate, whereas oleate selectively stimulates gluconeogenesis from lactate.