ULTRASTRUCTURE OF PAROTID AND MANDIBULAR GLANDS OF CAMEL (CAMELUS-DROMEDARIUS)

The structure of major salivary glands of camel (parotid and mandibula r) was studied by electron microscopy. The secretory units of parotid gland were tortuous and branched lined with cells of different heights , imparting a scalloped appearance to acinar lumina. Numerous microvil li were extending from cell membrane into the lumina and intercellular canaliculi. Secretory cells contained abundant mitochondria, less gra nular endoplasmic reticulum and less prominent Golgi apparatus as comp ared to those in the parotid gland of non-ruminant mammals. Two types of secretory granules variable in size and electron density, were pres ent in the acinar cells. Mandibular glands were compound tubulo-acinar and contained serous, mucous and seromucous secretory units. Secretor y cells contained heterogeneous secretory granules. The parenchyma of both the glands consisted of intercalated ducts which connected secret ory units with striated ducts. These ducts in turn opened into collect ing ducts located between gland lobules. Striated ducts within parotid gland were not so developed as those of mandibular glands. In latter, these ducts exhibited extensive basal infolding with abundant mitocho ndria similar to those in bovine glands. Myoepithelial cells were most often present at junctions of acini and intercalated ducts and in ass ociation with secretory units.