Studies of Liver Glycogenoses, with Particular Reference to the Metabolism of Intravenously Administered Glycerol

To investigate the pathophysiology of glycogenoses of the liver, glycerol, an endogenous precursor of glucose, was administered intravenously to eight patients and to 22 control subjects. Its disposal rate and effect on the levels of glucose and of lactate were measured. In all patients, particularly those lacking glucose-6-phosphatase, the disposal rate of glycerol was more rapid than in control subjects. Elevation of glucose levels was less than normal in the patients lacking glucose-6-phosphatase, and more than normal but with distinctive patterns in a patient deficient in amylo-1,6-glucosidase, and in two considered to lack a component of phosphorylase. Lactate levels were elevated only in patients lacking glucose-6-phosphatase. A single patient responded similarly to those lacking glucose-6-phosphatase but had normal enzyme activity in the liver on in vitro assay. This condition is proposed to be a variant of von Gierke's disease in which glucose-6-phosphatase activity, although present in vitro, is inactive in vivo.