The Glycogen Content of Human Leukocytes

Studies by Wagner (1) on the quantitative estimation of glycogen in human blood disclosed the average glycogen content per 100 ml. to be 5.5 mg. In separated leukocytes an average of 2.54 micrograms of glycogen was found per 106 total leukocytes, or 4.23 micrograms per 106 granulocytic leukocytes. No detectable glycogen is present in human plasma or erythrocytes. It has been both denied (2) and claimed (3) on the basis of histochemical data that lymphocytes and platelets contain small amounts of glycogen. The work of Wagner (1, 4), however, would indicate that the granulocytic leukocyte is probably the only significant representative of the white cells in the peripheral blood which contains glycogen. Studies on leukemic leukocytes (4) indicate that the blast cell contains no measurable amount of glycogen. Both histochemical studies (5) and the quantitative observations of Wagner (1, 4) suggest that glycogen first appears in the granulocytic leukocytes at the myelocytic stage and may increase with increasing cell maturity. Wagner (4) has observed a normal content of glycogen per 106 leukocytes in chronic myelocytic leukemia. In this laboratory, recent studies (6) have shown that whereas total leukocyte glycogen is frequently within the normal range, unit myeloid cell leukocyte glycogen is low. This is not explainable solely in terms of cell immaturity in the leukemic blood analyzed. In polycythemia vera of the type associated with leukocytosis and leukemoid reactions, the unit myeloid cell glycogen is substantially above normal (6). Wagner (4) has observed increased leukocyte glycogen values in polycythemia vera and Wachstein (5) has made similar qualitative observations on the basis of histochemical staining techniques. The leukocyte glycogen con-