SUBJECTS *

Many studies during the last decade have been concerned with the biochemical properties under-lying various states of the human red blood cell, including its maturation, aging, and some abnor-mal conditions. A considerable amount of work has been de-voted particularly to the study of erythrocyte metabolism in the fava bean- and drug-induced hemolytic anemias. Observations were first made by Beutler and his co-workers (1, 2) concerning the instability and decreased content of reduced glutathione (GSH) in red cells in drug-induced anemia. Carson (3) and Gross (4) and their colleagues, and Sansone and Segni (5, 6) demonstrated glucose-6-phosphate dehydrogenase (G6PD) deficiency in these cells. Further work has since been done in an attempt to find a link between the genetically determined metabolic de-fect and the hemolytic phenomenon. Such studies have been concerned mainly with the activity and properties of various enzymes, and some work in this field has been done also in our laboratory (7-10). In the present paper a somewhat different approach is described. Glu-cose metabolism in fava bean-sensitive versus nor-mal erythrocyte suspensions has been followed by quantitatively estimating the different metabolites that arise from its consumption in vitro. On these transformations, as well as on triose phosphate oxidation by hemolyzed red cells, the action of methylene blue (Mb) has also been studied