Heterogeneity of intact granules purified from canine mastocytoma cell lines

Abstract

We investigated the observation that some mast cells exhibit asynchronous release of granule-associated neutral proteases. Intact mast cell granules were isolated, purified, and studied with respect to their histamine, neutral protease, and proteoglycan content. Studies of two canine mastocytoma cell lines demonstrated differences in storage and packaging of granules within one of the cell lines (G) with respect to the neutral proteases and density, resulting in two distinct subpopulations of granules. By use of identical techniques no such differences were found in the other cell line (BR). These observations suggest that granule subpopulations in some mast cells may have a role in the differential release of mediators.