Different hormonal responses of mast cells in gastric mucosa and dermis in the rat.

The responses of the gastric mucosal mast cells and the subcutaneous mast cells of the abdominal skin of the rat after administration of ACTH, heparin, and asbestos, were studied. The superficial part of the gastric mucosa contained roughly 5 times as many mast cells as the subcutaneous connective tissue. About three-fourths of the gastric mucosal mast cells were degranulated under the influence of ACTH, but the subcutaneous mast cells showed no changes in number and granulation. The observed difference indicates possibly that mast cells in the gastric mucosa and in the epidermis may have important special, but clearly differing, functions. In the gastric mucosa the sensitiveness of mast cells is possibly connected with their function as a peripheral mediator of stimulation of gastric secretion.