Notably, in the sublingual gland, immunohistochemistry for neuron-specific enolase demonstrated that the serous acini carried a higher density of nerve elements than the mucous acini. submandibular gland, but not in the sublingual gland. Therefore, with regard to the neurogenic features of the gland cells, S100B reactivity might disappear first in postnatal life, whereas S100A reactivity is likely to remain as aging progresses. The sublingual gland in elderly individuals seems to provide a good model for comparison of the nerve supply between mucous and serous acini. test. Results PAS staining clearly demonstrated a mosaic pattern formed by the mucous and serous Alosetron Hydrochloride acini in the sublingual and submandibular glands (Figs. 1, ?,2,2, ?,3).3). The Alosetron Hydrochloride sublingual gland was comprised of 30-60 round or triangular lobules in each section, while the submandibular gland had 60-120 quadrate, triangular or irregularly shaped lobules per section. Although the present observations were not three-dimensional, the lobules of the sublingual gland were classifiable into three patterns: (1) lobules composed purely of mucous acini; (2) lobules composed purely of serous acini; and (3) lobules containing both types of acini (i.e., actual mixed glands). The mucous lobules numbered 3-8 per section (around 10%), the serous lobules 5-15 (around 20%), and the others-accounting for the majority-were regarded as mixed lobules. However, in the submandibular gland, the mucous acini, if present, were restricted to a small area in each lobule. Thus, the majority of lobules were serous, and mixed lobules accounted for less than 10% of the total. In the interlobar tissue, nNOS-positive as well as TH-positive sympathetic nerves were easily found. However, we were unable to trace them to areas around the acini because of the limited nature of the present IHC (Fig. 3). Open in a separate window Fig. 1 Sublingual gland obtained from an 83-year-old female cadaver. (A) Distribution of the mucous and serous glands: dark violet indicates the mucous glands (periodic acid Schiff staining). DCN One lobule (with square B) is composed of mucous acini, whereas the other Alosetron Hydrochloride lobule (with square C) contains only serous acini. Panels (B-D) show higher-magnification views of the squares marked B, C and D in panel (A), respectively (immunohistochemistry for neuron-specific enolase or neuron-specific enolase [NSE]). The lobule containing serous acini (C) shows a higher density of NSE-positive neural elements than the lobule containing mucous acini (B). (D) The border between the mucous and serous gland areas in a lobule (marked D in panel A) containing both types of acini. Scale bars=1 mm (A), 0.1 mm (B-D). Open in a separate window Fig. 2 Submandibular gland obtained from an 83-year-old female cadaver. (A) The distribution of the mucous and serous glands (periodic acid Schiff staining). The mucous gland acini are restricted to a small area in each lobule. Panels (B) and (C) show higher-magnification views of the squares marked B and C in panel (A), respectively (immunohistochemistry for neuron-specific enolase or neuron-specific enolase [NSE]). There is no clear difference in the density of NSE-positive neural elements between the area rich in mucous acini (B) and that rich in serous acini (C). Scale bars=1 mm (A), 0.1 mm (B, C). Open in a separate window Fig. 3 Innervation of the sublingual and submandibular glands obtained from a 78-year-old male cadaver. Using near sections, panels (A), (C), (E), (G), and (I) (or B, D, F, H, and J) display the Alosetron Hydrochloride sublingual (or submandibular) gland. Panels (C), (E), (G), and (I) (or D, F, H, and J) are higher-magnification views of the square in panel (A) (or panel B). Panels (A) and (B) show periodic acid Schiff staining: the sublingual gland contains an area of serous acini or lobules (serous in panel A), whereas in the submandibular gland the area of mucous acini is very limited (mucous in panel B). Immunohistochemistry for S100A protein (Z0311) (C, D), neuron-specific enolase (NSE) (E, F), neuronal nitric oxide synthase (NOS) (G, H), and tyrosine hydroxylase (TH) (I, J). Some of the myoepithelial cells and ductal cells are positive for S100 (arrowheads in panel C). Interlobar nerves express both NOS (arrows in panels G and H) and TH (arrows.