Determinations of activity of the globinase from Plasmodium berghei by radiometry with mouse [3H]globin as substrate

An induction of reticulocytes in mouse blood amounted to 60% was achieved by ip injection of phenylhydrazine hydrochloride 15 mg/kg twice a day for 8 d. [4,5-3H]leucine as a precursor was used to label the hemoglobin being synthesized in a cell-system in vitro consisting of the high percentage of reticulocytes. Then, [3H]globin was prepared from the [3H]hemoglobin. Assays of the activity of the globinase from P. berghei were performed using the [3H]globin as a substrate. There was no elevation in activity of the globinase from the strain of P. berghei resistant to hydroxypiperaquine than that from the ANKA strain of P.berghei sensitive to antimalarials. In the present paper, the affecting factors were also investigated on removal of white cells from malaria-infected blood and on determinations of activity of the globinase in the lysate or extract from P. berghei.