Local and Global Changes in Cytosolic Free Calcium in Neutrophils During Chemotaxis and Phagocytosis

Cell Calcium. Feb-Mar 1990;11(2-3):181-90. doi: 10.1016/0143-4160(90)90069-7.

Abstract

Neutrophils are capable of undergoing rapid directed movement up a concentration gradient of chemoattractant culminating in the phagocytosis of a target. We have developed a system to make rapid photometric measurements and ratio images of cytosolic free calcium [( Ca2+]i) in human neutrophils loaded with the fluorescent Ca2(+)-sensitive indicator Fura-2 during these processes. In our system neutrophils undergo chemotaxis toward and phagocytosis of IgG and IgM-coated sheep erythrocytes attached to a surface. During chemotaxis and phagocytosis, repetitive transients in [Ca2+]i take place. Accompanying the transients during phagocytosis is a localized [Ca2+]i increase in the periphagosomal region. This localized increase is more apparent in cells phagocytosing particles coated with both IgG and IgM than with IgM alone. No consistent localization of increased [Ca2+]i is seen in cells solely undergoing chemotaxis. The imaging techniques described here allow the observation of [Ca2+]i changes over regions of several microns 2 in a cell with a time resolution of approximately 0.5 s. [Ca2+]i gradients extending over regions greater than approximately 4 microns 2 and lasting at least 1 s can be reliably detected.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Benzofurans
  • Calcium / metabolism*
  • Chemotaxis, Leukocyte*
  • Cytosol / metabolism*
  • Fluorescent Dyes
  • Fura-2
  • Humans
  • Microscopy, Fluorescence
  • Neutrophils / immunology
  • Neutrophils / metabolism*
  • Phagocytosis*

Substances

  • Benzofurans
  • Fluorescent Dyes
  • Calcium
  • Fura-2