Mast cells in the human upper respiratory mucosa were investigated with respect to formalin sensitivity and berberine positive property which thought to be the difference of proteoglycan were contained. Sections were obtained by inferior turbinate mucosa of allergic and nonallergic state, maxillary sinus mucosa with chronic infection, and epipharynx mucosa with adenoid vegetation and after being fixed with Mota's lead acetate solution and 10% beffered formalin solution, these sections were stained with toluidine blue, alcian blue/safranin, and berberine-toluidine blue.
Mast cells could be divided into two groups which were formalin sensitive mast cells (FSMCs) and formalin resistant mast cells (FRMCs). The number of FSMC was more abundant in the epithelial layer than that of FRMC. These increase of FSMC in allergic nasal mucosa and maxillary sinus mucosa were greater than that in non-allergic nasal mucosa or epipharynx mucosa (p<0.05). On the other hand, more than 90% mast cells in the deep lamina propria were formalin resistant. These results indicate that mast cells in the human upper respiratory mucosa could be divided into two subpopulation by histochemical method. The character of these subpopulation was similar to those of mucosal mast cell (MMC) and connective tissue mast cell (CTMC) as in the rat. The positive mast cells with safranin which stained rat peritoneal mast cell and human skin mast cell with red, however, could not be identified in the human upper respiratory mucosa.
In nasal mucosa, it was suggested that FRMC contained heparin as one of proteoglycans, since FRMC showed strong fluorescence by berberine. Another interesting fact was that the number of FSMC increased remarkably in the epithelial layer of maxillary sinus mucosa with chronic infec tion, which might mean that FSMC had some role of infection.