Human gastric mucosal mast cells are chondroitin sulphate E-containing mast cells.

Our recent identification of chondroitin sulphate E-containing mast cells (E-MC) in the human colonic mucosa is extended here to the human gastric mucosa by using a combination of both biochemical and immunochemical approaches. Most of the mast cells in human gastric biopsies, which were located mainly around small blood vessels in the submucosa, showed various degrees of degranulation and were granular when stained by monoclonal antibody against chondroitin sulphate proteoglycan. The human gastric mucosa biopsies incorporated (35S)-sulphate into proteoglycans. Cells in the tissues which were histamine-positive also incorporated (35S). The 35S proteoglycans, which were either left associated with the tissue or released into the medium, were found not to be heparin but chondroitin sulphate E. Incubation of the human gastric mucosa biopsies in the presence of anti-human IgE revealed significant enhancement in the release of both (35S)-chondroitin sulphate E proteoglycan and histamine.