Loss of liver glycogen after administration of protein or amino acids

Abstract
Rats were given a meal of carbohydrate which caused deposition of glycogen in their livers, and were then fed on casein, glycine, alanine, glutamic acid or olive oil. The casein and the amino acids each caused a large loss of glycogen from the liver. This action was already considerable within 1 hr. of administration. There was no change in glycogen concentration 2 hr. after feeding olive oil. Coincident with the loss of liver glycogen after protein or amino acid administration, there . was a fall in blood-sugar concentration. There was no change in muscle-glycogen concentration. The feeding of protein or amino acids to adrenodemedullated rats or to alloxan-diabetic rats resulted in a loss of glycogen from their livers. It was concluded that secretion of adrenaline or of insulin is not an essential part of the mechanism responsible for loss of liver glycogen after protein administration. It is suggested that the loss of liver glycogen after administration of protein or amino acids is associated with the extra energy expended during the specific dynamic action of the absorbed amino acids.