5-Methyltetrahydrofolate related enzymes and DNA polymerase alpha
activities in bone marrow cells from patients with vitamin B12 deficient
megaloblastic anemia
Y Kano, S Sakamoto, K Hida, K Suda and F Takaku
The activities of 5-methyltetrahydrofolate (5-CH3THF) related enzymes and
DNA polymerase alpha were determined in bone marrow cells obtained from
patients with vitamin B12 deficient megaloblastic anemia and compared with
those from healthy volunteers and patients with hemolytic anemia. 5-CH3THF
homocysteine methyltransferase activity was significantly lower than that
in the control subjects. 5,10- methylenetetrahydrofolate reductase activity
was only slightly elevated to that in the control subjects. DNA polymerase
alpha activity was significantly higher than that in the control. High
deoxyuridine suppression test values in vitamin B12 deficient bone marrow
cells were improved by tetrahydrofolate, but not by 5-CH3THF. These data
indicate that, even though the reverse reaction catalyzed by 5,10-
methylenetetrahydrofolate reductase may be operative in vitamin B12
deficiency, it is not sufficient to correct the disturbance in folate
metabolism in vitamin B12 deficiency. Increased DNA polymerase alpha
activity may be due to compensation for disarranged DNA synthesis.
Volume 59,
Issue 4,
pp. 832-837,
04/01/1982
Copyright © 1982 by The American Society of Hematology
