Blood, 1960, Vol. 15, No. 3, pp. 360-369.
© 1960 American Society of Hematology, Inc.
Pyrimidine Metabolism in Man. II. Studies
of Leukemic Cells
LLOYD H. SMITH JR. 1,
FAITH A. BAKER 1, and
MARGARET SULLIVAN 1
1 Huntington Memorial Laboratories and the Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Mass.
1. The activities of three enzymes involved in pyrimidine synthesis—
aspartate carbamyltransferase, dihydro-orotase and dihydro-orotic dehydrogenase—were studied in sonicates of circulating leukocytes from 5 patients with
myelocytic leukemia, 2 with lymphocytic leukemia, 2 with myeloproliferative
disorders and 5 with infection. The erythrocytes from one patient with the
Di Guglielmo syndrome were studied.
2. Neoplastic cells showed increased activities of all three enzymes tending
to parallel the cytologic evidence of immaturity. The increase of dihydroorotic dehydrogenase was the most striking abnormality. Leukocytes from
patients with infection or with myeloproliferative disorders showed similar
but much less marked alterations in the enzyme pattern.
3. Dihydro-orotic dehydrogenase, absent from mature erythrocytes, was
present in the nucleated erythrocytes in the Di Guglielmo syndrome.
4. The enzyme 5 carboxymethylhydantoinase, previously found in some
bacteria, was absent from normal and abnormal hemic cells.
Submitted on June 30, 1959
Accepted on September 27, 1959
