[Vitamin B12 metabolism of human granulocytes. Differences in vitamin B12 uptake of normal granulocytes and CML leukocytes].

The total cell B12 level in chronic myelocytic leukaemia (CML) is low. The uptake of 57Co-cyanocobalamin by normal granulocytes, lymphocytes and CML leukocytes was studied. It was found that the uptake of vitamin B12 was dependent on its concentration. The velocity of the uptake by CML leukocytes was decreased. The reaction showed a non-competitive inhibition. Lymphocytes had the lowest uptake. Na2EDTA inhibited the vitamin B12 uptake of normal granulocytes.