Abstract
1) A highly elevated level of erythrocytic arginase (thirty times higher than normal) was found in a patient with sideroblastic anemia.
2) Urea cycle enzyme actvities in the erythrocytes of the patient were determined and compared to those of normal ranges.
3) Characterization of arginase of the patient was presented: Km value, optimum pH, stability and amino acid inhibition were the same as those of normal arginase.
4) No inhibitor of arginase was detected in erythrocytes of the patient.
