Membrane permeability in normal human lymphocytes and lymphocytes from patients with chronic lymphatic leukaemia

The rate of release of intracellular enzymes from the lymphocytes of patients with chronic lymphatic leukaemia has been shown to be slower than that from normal lymphocytes, despite their lower enzyme contents. Addition of ATP, ADP and AMP to the medium reduces enzyme efflux in a manner similar to that in normal lymphocytes. Iodoacetate, however, causes a marked increase in enzyme leakage from both normal and leukaemic cells. It appears therefore that the membrane permeability of leukaemic lymphocytes is at least partly dependent upon the intracellular energy content. Since the ATP contents of the leukaemic cells were lower than those of normal lymphocytes, however, it is concluded that some additional factor is concerned in reducing permeability to enzymes in chronic lymphatic leukaemia. The possibility that the immunoglobulin associated with the cell membrane of leukaemic cells may play a part in reducing its permeability has been explored, but washed and unwashed cells were found to lose enzymes at similar rates. The lower permeability of the membranes of such cells may partly explain their longer lifespan in chronic lymphatic leukaemia.