The cation-sensitive phosphatases of the leucocyte cell membrane

Leucocidin induces in polymorphonuclear leucocytes changes that mimic those in excitable or secreting tissues. Thus the permeability to cations increases, proteins of the cytoplasmic granules are secreted and calcium is accumulated in vesicles. The earliest response of the cell appears to be the increased cation permeability. The leucocyte differs from other mammalian cells in having a high sodium content ( Elsbach and Schwartz, 1959) and in regulating the electrolyte balance by controlling the potassium content. Woodin and Wieneke (1968) suggested that leucocidin induces a structural change in the potassium pump, and, as tetraethylammonium ions inhibited the potassium efflux, that the changes induced by leucocidin might be relevant to membrane depolarisation in peripheral nerve. The present paper shows that the peculiarities of electrolyte control in the leucocyte correlate with the properties of the cation-sensitive phosphatases and that leucocidin alters the potassium-sensitive component. The study was made possible because fragments of the leucocyte cell membrane can be unambiguously identified in cell homogenates ( Woodin and Wieneke, 1966a).