Regional and generalized changes in cytosolic free calcium in monocytes during phagocytosis

Abstract

We measured and visualized cytosolic free calcium ([Ca2+](i)) in individual human peripheral blood monocytes during phagocytosis by using the fluorescent indicator fura-2. Monocytes exhibit a rapid rise in [Ca2+](i) from a basal level of 75 ± 11 nM to a peak level of 676 ± 78 nM (means ± standard errors of the means; P < 0.001) by 34 ± 5 s after contact with opsonized zymosan particles, and a thin rim of high [Ca2+](i) was observed surrounding the ingested particle.