An innovative technique for isolating functional mast cells from the heart

Abstract

Cardiac mast cells are key players in pathological remodeling of the myocardium. However, the previously described procedures for isolating mast cells from the heart, which require enzymatic digestion of the myocardial tissue, result in a relatively low yield of mast cells with limited functionality. We have developed a protocol, whereby Hanks balanced salt solution is injected into the pericardial sac and then aspirated, drawing with it cardiac mast cells. The resulting preparation contains a greater number of mast cells of higher purity than could previously be obtained using traditional isolation techniques. Mast cells isolated by this new technique have low basal rates of spontaneous histamine release and are highly responsive to the secretagogue, compound 48/80. These cardiac mast cells were of the connective tissue type, based on the presence of chymase and tryptase demonstrated within the cells by immunofluorescence and western blotting. This cellular phenotype is consistent with the previously reported characterization of cardiac mast cells isolated from the heart by enzymatic dispersion techniques. Accordingly, this novel technique for the isolation of cardiac mast cells provides a powerful tool by which to characterize and study functional cardiac mast cells in an in vitro environment, allowing for development of a greater understanding of their role in myocardial disease. This study was supported in part by NIH R01-HL62228 (JSJ), R01-HL073990 (JSJ)