Blood Journal
Leading the way in experimental and clinical research in hematology

Glycogen Metabolism in the Normal Red Blood Cell

  1. Shimon W. Moses, M.D., Head of Pediatrics "B" and Pediatric Research,
  2. Nava Bashan, M.Sc., Research investigator, and
  3. Alisa Gutman, M.D., Senior Lecturer
  1. Pediatric Research Laboratory, Negev Central Hospital and Negev University, Beer Sheva, and Department of Biochemistry, Hebrew University, Hadassa Medical School, Hadassa, Jerusalem, Israel.
  2. Soroka Medical Center; Senior Lecturer, Negev University, Beer-S heva, israel.
  3. Pediatric Research, Soroka Medical Center, Beer-Sheva, Israel.Alisa Gutman,
  4. Clinical Biochemistry, Department of Biochemistry,Hebrew University, Hadassa Medical School, Jerusalem, Israel.

Abstract

Evidence for active glycogen metabolism in normal mature red blood cells (RBC) is presented. Initial rates of 14C-U-glucose incorporation into erythrocyte glycogen were found to be independent of substrate concentration over a range of 3.3-16.6 mM. Incorporation of label into glycogen was initially linear but reached a plateau after a variable period of time that was inversely related to RBC concentration in the medium. The major part of the incorporated radioactivity resided in the outer branches of the glycogen molecule. The optimum pH for 14C-U-glucose incorporation into glycogen was pH 7.6. Replacing the radioactive glucose employed for incorporation after 1 hr of incubation with nonlabeled glucose resulted in a gradual loss of radioactivity from erythrocyte glycogen. In normal cells, glycogen synthesis and breakdown do not result in any significant accumulation of glycogen, whereas in erythrocytes with enzyme defects affecting glycogen breakdown, substantial deposition of glycogen may be observed.

  • Submitted March 10, 1972.
  • Revision received July 7, 1972.
  • Accepted July 10, 1972.