Leucocyte sodium-potassium adenosine triphosphatase and leukemia.

Na-K ATPase of healthy leucocytes is relatively low (109 +/- 20 nmol . mg-1 . h-1), as is the permeability of the plasma membrane to cations. In this study of leucocytes from leukaemic patients, the Na-K ATPase was increased. There was an associated increase in membrane permeability to sodium and calcium. In one patient, this led to a clinically dangerous and spurious suggestion of hyperkalaemia. It is suggested that some leukaemic conditions may be associated with 'leaky' membranes.