Carbohydrate synthesis from lactate in pigeon-liver homogenate

Abstract

A cell-free pigeon-liver homogenate is described that readily synthesizes carbohydrate from lactate (about 50 [mu]oles/g. of liver /hr. ). Essential components for maximum rates are Na+ and K+ ions, EDTA, phosphate, Mg2+ ions, bicarbonate and NAD. Glucose is the main carbohydrate formed; glycogen appears in minor quantities. The rates of carbohydrate synthesis are higher in the livers of starved than in those of well-fed animals. Fumarate, glutamate, [alpha]-oxoglutarate, glycerol and glycerophosphate also form carbohydrate in the pigeon-liver homogenates, but the rates are lower than with lactate. ATP and AMP inhibit gluconeogenesis and accelerate the disappearance of carbohydrate in the absence of lactate.