Glucose and glycogen metabolism in erythrocytes from normal and glycogen storage disease type III subjects

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Abstract

Active glycogen metabolism has been demonstrated in both normal and glycogen-rich erythrocytes taken from patients with type III glycogen storage disease. Activity of all enzymes catalyzing the reactions required for the synthesis and degradation of glycogen have been demonstrated in the mature erythrocytes. Uniformly labeled glucose-14C is incorporated into glycogen in intact cells of both types during incubation. Replacement of the glucose-14C by unlabeled glucose in the medium resulted in a significant loss of radioactivity from cellular glycogen. In the absence of the substrate a progressive shortening of outer branches occurred during incubation of intact glucogen-rich cells. Using cells from patients with type III glycogen storage disease, which have sufficient glycogen content to be analyzed by β-amylolysis, we demonstrated that the glucosyl units are first incorporated in the outer tiers, then transferred to the core where they tend to accumulate due to the absence of amylo-1,6-glucosidase.

Authors

Shimon W. Moses, Reuben Chayoth, Stanley Levin, Ela Lazarovitz, David Rubinstein