Ultrostructural and immunohistochemical observation of plasma cells of the human labial glands *
Plasma cells in the human labial glands were examined ultrastructurally and immunohistochemically. For electron microscopic observation, labial mucosa removed from four cadavers, 61―78 years of age, were fixed in Ｋarnowsky's fluid and embedded in Epon812. To detect immunoglobulin Ａ, Ｇ and Ｍ, labial mucosa were removed from a cadaver fixed by perfusion with ５％ formaldehyde, refixed in 3.5％ paraformaldehyde, and embedded in paraffin. Immunohistochemistry using the avidin-biotin peroxidase complex (ＡＢＣ) method was performed. Secretory portions of normal labial glands were composed of numerous seromucous-producing cells and a few serous-producing cells. The connective tissue surrounding secretory portions contained a number of plasma cells with abundant rough endoplasmic reticulum (ＲＥＲ), The majority of the ＲＥＲ had distended profiles over 100 nm in width. A few plasma cells with Russell bodies appeared in the connective tissue surrounding secretory acini. Two kinds of inclusions were found in the cytoplasm of the plasma cells ; bicylindrical ribosome-lamellae complexes and intracisternal crystals. The latter inclusions appeared in the distended cisternae of the ＲＥＲ. Large numbers of plasma cells around secretory acini were stained by ＩｇＡ, and a few plasma cells were ＩｇＧ positive. Plasma cells with Russell bodies were ＩｇＭ positive. Both ＩｇＡ and ＩｇＧ positive reactions were also found in some of the seromucous-producing cells of secretory acini. Lumina of secretory acini as well as some of the epithelial cells of intercalated ducts were also stained ＩｇＡ and Ｇ positive. The connective tissues surrounding secretory acini were diffusely ＩｇＭ positive . The relationship between plasma cells in labial glands and secretory ＩｇＡ in saliva was discussed. (Accepted on August 15, 1997) Kawasaki Igakkaishi 23(2) : 87-97. 1997
