The Haemolytic Action of Dapsone: The Effect on Red‐Cell Glycolysis

Summary. Some aspects of red‐cell metabolism were studied in blood samples taken from patients on long‐term dapsone therapy. Glucose consumption by the Enibden‐Meyerhof pathway (EMP) was not abnormal and adenosine‐triphosphate (ATP) levels lay within the normal range and were well maintained during incubation. Hexose monophosphate pathway (HMP) activity was increased above that which would be expected from the age of the red‐cell population. Red‐cell reduced glutathione (GSH) levels tended to be lower than normal, proportional to the dose of dapsone and GSH levels were unstable on incubation. Red‐cell fractionation studies showed that the older cell fraction had lower GSH levels and more Heinz bodies but proportionally greater HMP activity than the younger cell fraction. It is suggested that the low GSH levels are probably due to the binding of GSH to sulphydryl groups in haemoglobin and possibly the red‐cell membrane. The increased HMP activity in the older cells may, in part, be a compensatory mechanism.