Biochemical and histochemical studies on the distribution of histamine in the digestive tract of man, dog and other mammals.

Abstract

1. The distribution of histamine was determined in tissues of the digestive tract of man, dog, pig, cow, and sheep, especially in the oral mucosa, stomach, gallbladder, and pancreas. 2. After treatment with compound 48/80, histamine was released from the frenulum linguae, soft palate, tongue, and thyroid gland of dogs, but not from the vestibulum oris, hard palate, pharynx, oesophagus, stomach, and pancreas (experiments in the dog). The release of histamine from the tongue showed regional differences and was lowest in the root and highest in the tip. 3. A parallelism could be shown between the histamine content and the mast cell density in different parts of the tongue, stomach and in the soft palate of untreated dogs and dogs treated with 48/80. The mast cells in the gastric mucosa could be characterized by their staining properties as “atypical” mast cells, whereas those in the musculature of the tongue were “typical” mast cells. 4. The histamine content of the single mast cell was similar in all tissues (3.2 pg/ cell in the tongue, 3.3 in the stomach, 4.8 in the soft palate and 3.4 in the submaxillary gland). Only the mast cells in the fundic mucosa showed a significantly lower histamine content (1.9 pg/cell). The mast cells of the fundus and body of the stomach of the dog seemed to store histamine which was released by 48/80. 5. A new classification of histamine stores is proposed: “unspecific mast cell stores” and “tissue specific stores”.