The microanatomy of calcium stores in human neutrophils, Relationship of structure to function

Abstract

As changes in cytosoiic free ca2+ play key roles in coupling responses in neutrophils, it is important to locate and identify ca2+ storage sites within these cells. Here, recent data is presented which highlights the functional link between rnicroanatomical structure and cell signailing function. Fluorescent opticai probes for cytosolic free ca2+ have been used, together with organelle specific markers. We present evidence from conventional fluorescence microscopy, together with ratiometric and confocal laser scanning fluorescence microscopy, which pin-points two celiular locations for ca2+ within the neutrophil; one within the nuclear lobes, and the other towards the ceii periphery. Knowledge of these two locations provides a clear insight into how signailing in this cell type is regulated and provides a framework for explaining how specific stimuli act to produce specific responses.