title: Innervation of submandibular and sublingual glands in elderly donated cadavers: a preliminary histological study of differences in nerve morphology between mucous and serous acini.
abstract: We examined morphological differences between the sublingual and submandibular glands with special reference to their innervation. The sublingual gland contained abundant periodic acid Schiff-positive mucous acini: some lobules were composed of purely mucous acini, while others were purely serous or mixed. However, in the submandibular gland, the area of mucous acini was very limited. 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. However, no such difference was evident in the submandibular gland, possibly due to the small areas of the mucous acini. In both types of gland, neuronal nitric oxide synthase-positive parasympathetic nerves as well as tyrosine hydroxylase-positive sympathetic nerves were observed in the interlobular tissue, but we were unable to trace these thin fibers to the acini. Myoepithelial cells expressed smooth muscle actin, but were negative for S100B protein, glial fibrillary acidic protein and neuron-specific enolase. However, antibody against S100A stained some of the myoepithelial cells and ductal cells in the sublingual gland. Cells positive for peripheral myelin protein 22 were seen in some of the ductal cells in the 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.
authors: Department of Anatomy, Tokyo Dental College, Tokyo, Japan.
authors: Sachiko
authors: S
authors: Asakawa
authors: Department of Anatomy, Tokyo Dental College, Tokyo, Japan.
authors: Masahito
authors: M
authors: Yamamoto
authors: Department of Otolaryngology-Head and Neck Surgery, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors: Yukio
authors: Y
authors: Katori
authors: Division of Internal Medicine, Iwamizawa Asuka Hospital, Iwamizawa, Japan.
authors: Gen
authors: G
authors: Murakami
authors: Department of Anatomy, Tokyo Dental College, Tokyo, Japan.
authors: Masaaki
authors: M
authors: Kasahara
authors: Department of Anatomy, Tokyo Dental College, Tokyo, Japan.
authors: Satoru
authors: S
authors: Matsunaga
authors: Department of Anatomy, Tokyo Dental College, Tokyo, Japan.
authors: Shin-Ichi
authors: S
authors: Abe
keywords: Mucous acinus; Nerve; Serous acinus; Sublingual gland; Submandibular gland