The accumulation of calcium by the polymorphonuclear leucocyte treated with staphylococcal leucocidin and its significance in the extrusion of protein

Abstract

After treatment with leucocidin there is a loss of magnesium from and a gain of calcium by the leucocyte. The accumulation of calcium occurs if the calcium is added to the leucocidin-treated cell at 0[degree]. Mechanically disintegrated leucocytes adsorb calcium from solution. There is no difference in the amount adsorbed by disintegrated normal or leucocidin-treated cells. When calcium is omitted from the medium the extrusion of protein from the granules of the leucocidin-treated leucocyte is inhibited and the cell simultaneously becomes more permeable to orthophosphate and to aldolase. When calcium is added to leucocidin-treated leucocytes suspended in calcium-free media the release of [beta]-glucuronidase from the granules is induced. The amount released decreases as the period of incubation in calcium-free media is increased. The loss of efficiency of calcium in inducing extrusion of [beta]-glucuronidase can be prevented if nucleoside phosphates are added to the leucocytes in calcium-free media. There is no increased hydrolysis of adenosine triphosphate or accumulation of orthophosphate in the leucocidin-treated leucocyte when extrusion of [beta]-glucuronidase is induced by adding calcium. The presence of a nucleoside triphosphatase in the granules of the leucocyte is described. This is activated by calcium or magnesium and small differences can be detected in the activity of granules from normal or leucocidin-treated cells. The role of calcium, leucocidin, nucleoside phosphates and the equipment of the normal leucocyte in the process of extrusion of protein from the granules is discussed.