Isolation of histamine-containing cells from canine fundic mucosa.

The cells of the fundic portion of canine gastric mucosa were dispersed by collagenase digestion and separated into fractions by sequential use of velocity sedimentation in an elutriator rotor followed by a density gradient separation. There was a close correlation between histamine content and number of mast cells in the different cell fractions. The mast cells possessed characteristic dense granules, which stained metachromatically, but did not release histamine on exposure to Compound 48/80. The most highly purified fractions contained 80% mast cells and a histamine content of 2.5 pg/mast cell.