Cytosolic Ca2+ Measurement and Imaging in Inflammatory Cells

The ability to measure and manipulate cytosolic free Ca²⁺ concentration is important for understanding many aspects of the physiology of inflammatory cells. The evidence for the role of this ion in triggering and controling neutrophils, monocytes, lymphocytes, and others cells relevant to inflammation is accumulating. Although each cell type may differ in the detail, there are some general principals for measuring cytosolic free Ca²⁺ that apply to all these cell types. The methods most applicable to inflammatory cells mainly revolve around the use of fluorescent indicators and photoactive reagents. These can be loaded into the cells as lipid-soluble esters or can be microinjected into the cell. In this chapter, we will outline some of the techniques that have been used to monitor, visualize, and manipulate Ca²⁺ in inflammatory cells. For specific details relating to neutrophils, see ref. 1 and for details of other methods, such as the expression of luminescent and fluorescent indicators of Ca²⁺ , see ref. 2 .