Fine Structure of the Mandibular Gland of Chinese Hamster (<I>Cricetulus griseus</I>)

Abstract

The mandibular glands of the Chinese hamster were examined by light and electron microscopy. The mandibular acinar cells were noted to be categorized in a seromucous type, because the acinar cells stained slightly basophile and moderately positive for periodic acid-Schiff (PAS) and alcian blue (AB) reactions and the intercellular canaliculi were detected in the cells. The acini were composed exclusively of light cells containing various secretory granules. The acinar cells exhibited a sexual dimorphism ; in the female AB staining was more intense, and also the granules having the matrix of a fine hair-like material were more numerous than in the male. Intercalated duct cells were composed exclusively of light cells and contained round and polygonal granules. The striated ducts consisted of two distinct portions, the secretory and typical striated portions without secretory granules. The epithelial cells of secretory portion were columnar in shape and contained acidophile granules which gave a strongly positive PAS reaction, and comprised light and dark cells containing secretory granules varying in size and density. The epithelium of typical striated portion was composed of both light and dark cells containing fine vacuoles and vesicles, but no secretory granules. No sexual dimorphism was detected in the striated duct.

Fine Structure of the Parotid and Mandibular Glands of the Cotton Rat (Sigmodon hispidus)

“…The striated ducts of the mandibular gland in most rodent species are comprised of two portions: a proximal secretory portion and a distal typically striated portion without granules. In this study, the secretory portion of the cotton rat was similar to Syrian, Djungarian and European hamsters, mice and rats and exhibited sexual dimorphism unlike the secretory portion of the mandibular gland of Chinese [16], Syrian [2,3,8,9] and Djungarian hamsters [12]. In the present study, nerve terminals were observed in the acini of the parotid gland.…”

“…The parotid and mandibular intercalated duct cells of the cotton rat contained a few electron-dense granules and poorly developed cytoplasmic organelles. Their appearances were similar to those of parotid and mandibular glands of Chinese [14,16], Syrian [4], European [9] and Djungarian hamsters [11,12], mice and rats [6,7]. As regards the striated duct, that of the parotid gland of the cotton rat was similar to those of Syrian, Djungarian and European hamsters, mice and rats.…”

“…As for secretory granules, the parotid acinar cells of the cotton rat had one granule type unlike Chinese [14], Djungarian [11], European and Syrian hamsters [4,9] which have several granule types. The mandibular acinar cells of the cotton rat contained 2 kinds of granules unlike Chinese hamsters [16], Djungarian hamsters [12] and Japanese field voles [13] contain at least 4 kinds of granules. These morphological differences of secretory granules between the cotton rat and other rodent species may be greatly dependent on the protein contents of the granules [20].…”

“…The parotid acini consisted of serous cells that are PAS-positive and AB-negative in Syrian hamsters [4], Chinese hamsters [14], mice [10], rats [10], and seromucous cells have a PAS-and ABpositive nature in Djungarian hamsters [11] and ginea pigs [3]. As for the mandibular gland in rodent species, there are several reports describing that the acinar cells are of a seromucous type with a PAS-and ABpositive nature [2,8,12,13,16]. From these reports and our observations, we categorized the parotid acinar cells as serous and the mandibular acinar cells as seromucous in type.…”

Fine Structure of the Mandibular Gland in Crest-tailed Marsupial-rat (<I>Dasyuroides byrnei</I>)

“…Fine structures of the mandibular glands are reported in many mammalian species and show great variety in the form and configuration of the acini and striated ducts. The mandibular glands of many rodents [4,7,17,21,22,25], rabbits [2,29] and volcano rabbits [23] have acini consisting of only one cell type and are homocrine, possessing only seromucous cells. On the other hand, the mandibular glands of dogs [26], cats [5,18], pigs [18], horses [27], kobe mole [8] and several ruminant species [19,24,26] are composed of acini of two different cell types and are heterocrine, possessing mucous and seromucous cells with a PAS-, AB-positive nature.…”