Lectin Histochemistry of Glycoconjugates in Horse Salivary Glands

The glycoconjugate content of major horse salivary glands was investigated by means of horseradish peroxidase-conjugated lectins. Qualitative differences were observed in the terminal sugar residues of secretory glycoproteins and glycoconjugates linked to the apical surface of excretory duct epithelial cells. Mucous acinar cells in mandibular and sublingual glands contained oligosaccharides with D-galactose, α- and β-N-acetylgalactosamine, N-acetylglucosamine and fucose residues, whereas mandibular, sublingual and parotid serous cells contained only oligosaccharides with terminal α- and β-N-acetylgalactosamine residues. The apical portion of striated and interlobular duct lining cells of mandibular and sublingual glands stained for α- and β-N-acetylgalactosamine and for N-acetylglucosamine. In parotid gland the cytoplasm of intercalated duct cells and the apical surface of striated duct epithelial cells stained for α-N-acetylgalactosamine.     

CT sialography in the dog - a cadaver study

To document computed tomographic topography of salivary glands and their ducts in dogs, a retrograde filling with methylcellulose and iodinated contrast medium was performed in three cadavers. Demarcation of the parotid, mandibular and zygomatic glands was achieved. Surrounding structures were imaged without beam hardening artefacts. Landmarks for the parotid, mandibular and zygomatic glands were the external acoustic canal, the mandibular angle and the pterygopalatine fossa, respectively. Sialograms of the parotid, mandibular and zygomatic ducts were achieved, whereas neither the sublingual glands nor their ducts could be contrasted. The images provide a three-dimensional visualization of the salivary glands and their ducts.     

Sialography of sheep parotid and mandibular salivary glands

The anatomy of ovine salivary glands was studied on cadaver heads. The mandibular duct enters the oral cavity on the ventral surface of sublingual caruncles, which are located medial to the orifice of the ventral sublingual gland duct. The parotid gland duct enters the oral cavity on the cheek opposite the upper 2nd molar. Prior to applying sialography to live animals, the procedure was carried out on cadaver heads then the live animals were sedated, the mandibular and parotid ducts catheterized and contrast medium was injected into each gland. Lateral radiographs were made immediately after the injection. The normal sheep mandibular and parotid salivary glands have a multilobular appearance in cadaver heads, but in live animal only the ducts and their smaller branches could be identified. The mean diameter of mandibular and parotid duct were 1.4+/-0.3 mm and 3. 1+/-1.0 mm respectively. The monostomatic sublingular gland had a slender shape in the sialogram. In conclusion sialography of mandibular, parotid and sublingual salivary glands in sheep is practical and can be helpful in diagnosis of pathological conditions of these glands.     

Histochemistry of Complex Carbohydrate in the Major Salivary Glands of Hoary Bamboo Rats (Rhizomys purinosus)

The major salivary glands (parotid glands, monostomatic sublingual glands and submandibular glands) were obtained from hoary bamboo rats (Rhizomys purinosus) and fixed in Bouin's solution. Paraffin sections were subjected to a battery of staining methods including lectin staining for demonstration of complex carbohydrates. Among the three major salivary glands, unique histochemical features were observed in the submandibular gland. Different from most myomorpha species, submandibular glands of the hoary bamboo rats have two types of secretory cells in the secretory endpieces. One type of cells showed positive reactions with Alcian blue (AB)(pH2.5), periodic acid-Schiff (PAS) and some lectins (peanuts agglutinin, Griffonia simplicifolia I. Machura pomifera agglutinin). The granular ducts, which exist in animals belonging to suborder myomorpha, were not observed in the submandibular glands of this animal.     

Immunohistochemistry of carbonic anhydrase isozymes (CA-I, II and III) in canine salivary glands: a distributional and comparative assessment

The immunohistolocalization of carbonic anhydrase isozymes (CA-I, II, III) in canine salivary glands was studied using antiserum against CA-I, II, III. In parotid glands, immunostaining intensely localized cytosolic CA-II antiserum throughout the cytoplasm of acinar secretory cells and ductal epithelial cells, especially in the striated duct region. CA-III reactivity in the glands was only seen selectively at the intercalated ductal cells. In contrast, no immunoreaction localized CA-I in the gland. In the submandibular and sublingual glands, CA-I, II, and III were all observed in the ductal segments of the glands, whereas serous demilune appeared devoid of all three cytosolic CA isozymes. In contrast, in zygomatic glands (i.e. dorsal buccal glands) all CA isozymes were observed in both serous demilune and ductal segments. In all of the salivary glands examined, no mucous acinar cells were found to be reactive for any CA.     

Immunohistochemistry of the bovine secretory carbonic anhydrase isozyme (CA-VI) in bovine alimentary canal and major salivary glands

In the present study, we firstly demonstrated immunohistochemical expressions of secretory carbonic anhydrase (CA-VI) isozyme in bovine forestomach, large intestine and major salivary glands. CA-VI was detected in basal layer epithelial cells of esophageal and forestomach stratified epithelium, in mucous cells of upper glandular region of large intestine, in serous acinar cells of the parotid gland, in serous demilune cells and some ductal liner cells of mandibular, monostomatic sublingual and esophageal glands. These immunohistolocalizations suggested that bovine CA-VI plays various roles in pH regulation, maintenance of ion and fluid balance, and cell proliferation.     

SIALOGRAPHY IN CATTLE: TECHNIQUE AND NORMAL APPEARANCE

Sialography of the bovine mandibular and parotid salivary glands was performed by injecting iodinated, water soluble contrast medium into the respective ducts. The anatomy of the above mentioned salivary glands was studied on cadaver heads. The mandibular duct enters the oral cavity on the ventral surface of the sublingual caruncles, which are located medial to the orifice of the ventral sublingual gland duct. The parotid gland duct enters the oral cavity on the cheek opposite the upper 2nd molar (Sth cheek tooth). Prior to applying sialography to live animals, the technique of catheterization, injection and radiography had to be developed, which was carried out on cadaver heads. Subsequently the technique was applied to 5 live animals. The animals were sedated, the mandibular and parotid ducts catheterized, and contrast medium was injected into each gland. Latero-lateral radiographs were made immediately after the injection. The normal bovine mandibular and parotid glands, as depicted on sialograms, have a multilobutated appearance in cadaver heads, but in the live animal only the ducts and their smaller branches could be identified. The parotid duct leaves the deep surface of the rostral end of the gland and courses along the border of the masseter muscle before it enters the mouth. The mean diameter of the duct was 4.2 ± 0.3 mm. The mandibular duct is composed of a rostral and a caudal branch. The caudal branch describes a semi circular turn prior to joining the rostral branch. The mean diameter of the main duct was 2.8 ± 0.4 mm.     

Structural Changes of Goat Parotid Salivary Gland: Pre‐ and Post‐Weaning Periods

Previously, the structure of the adult goat parotid salivary glands (PGs) was studied. However, little information was elucidated of the juvenile ones. This study aimed to clarify the correlations between the structure of goats' PGs and the nature of food intake among milk‐suckling kids (MSKs) and diet‐fed goats (DFGs). The secretory endpieces of the goats' PGs are of the pure serous type. The serous cells in MSKs showed apical accumulation of numerous secretory granules (SGs) of smaller size and of more intense positive periodic acid‐Schiff reaction. Ultrastructurally, most of the SGs in the DFGs contained peripherally located inclusions that showed dense reaction products for acid phosphatase. In MSKs, the PGs showed less‐developed basal infoldings, sparseness of the inter‐cellular inter‐digitations, fewer inter‐cellular canaliculi and microvilli and also less‐developed myoepithelial cells with fewer and shorter cytoplasmic processes. In conclusion, the less‐developed membrane specializations and myoepithelial cells, as well as the accumulated SGs in the PGs of MSKs, suggest that it secretes less saliva with a little secretory activity than that of DFGs, which may be correlated with the reduced masticatory activity.     

Zur pränatalen Entwicklung der Glandula mandibularis und Glandula parotis der Katze

The prenatal development of the cat's mandibular and parotid gland was examined by means of serial section of 36 cat embryos at 14–62 days of development. Both glands were excised from the epithelium of the primitive oral cavity and branched up to day 36 of the branching phase into a specific connective tissue. This tissue contained besides fine collagenous fibres, a high amount of proteoglycans. In the subsequent separation phase, ducts and acini differentiated themselves in primitive lobules which were separated by connective tissue. In the prenatal differentiation phase, from about day 50 up to birth, intercalated ducts and striated ducts were formed. In the acini, mucous and serous cells contained different amounts of complex carbohydrates. This secretory component changed shortly before birth.     

Histology and histochemistry of the major salivary glands in the southern white-breasted hedgehog (Erinaceus concolor)

This study aimed to investigate the major salivary glands in the southern white-breasted hedgehog (Erinaceus concolor) histologically and histochemically. Five adult males were included in this study. The results showed that anatomically the shape of the parotid, submandibular and sublingual glands of the Erinaceus concolor was respectively almost pear, elliptical to pyramidal and oval. Histologically, the parotid gland had serous acini and secretory cells showed negative reaction to alcian blue (AB) (pH = 2.5) and negative response to aldehyde fuchsin (AF), methylene blue (MB) and PAS stains. The submandibular gland was a mixed gland of mucous and serous acini. The mucous acini were strongly positive for PAS, AB, MB and AF. However, serous acini were week for PAS and negative against AB, MB and AF stains. The sublingual gland was purely composed of mucous acini. The mucous acini of the sublingual gland were strongly positives for PAS, AB and MB methods. While their reaction to the AF staining was negative. In conclusion, the histological and histochemical observations of the major salivary glands of the southern white-breasted hedgehog (E. concolor) indicated that these glands shown similarities and some special different histochemical features as compared to other mammalian species.     

Microscopy of the echidna sublingual glands

The secretory units and duct system of the echidna sublingual glands exhibit subtle architectural modifications to accommodate the viscous secretion produced by these glands. The glands are compound tubular glands, the secretory units of which are elongate with open lumina and consist only of mucous cells. Closely packed spindle-shaped myoepithelial cells invest the secretory units, but are absent around the ducts. The branched secretory tubules open into an abbreviated duct system characterized by wide lumina. Striated ducts normally associated with the second portion of the intralobular duct system are absent. The duct system shows the most obvious modification of general salivary gland architecture presumably to accommodate the viscous secretion propelled from the secretory units by surrounding myoepithelial cells.     

MR anatomy of salivary glands in the dog

This retrospective analysis documented the magnetic resonance imaging (MRI) appearance of normal salivary glands based on 101 studies in dogs with no detectable disease in the splanchnocranium. Surface, signal intensity, homogeneity, structure, symmetry and the relationship of glands to surrounding tissues were noted, and gland topography was assessed with E12 plastinated embedded sections. Signal intensity of salivary glands was isointense (7-40%) to hyperintense (60-90%) to muscle tissue on T1- and hyperintense on T2-weighted images. Salivary glands had an increased T1 signal after contrast medium was applied. Salivary gland structure appeared homogeneous in mandibular and major sublingual glands and heterogeneous in zygomatic and parotid glands. Consistent landmarks were the external auditory canal for parotid glands, the digastric muscle for mandibular and major sublingual glands, and the pterygopalatine fossa for zygomatic glands. The minor sublingual and ventral buccal glands could not be localized with low-field MRI.     

Intestinal choristoma in the midcervical region of a dog

A 5-year-old, neutered male, mixed-breed dog was evaluated for a fluctuant mass in the right midcervical region. The mass recurred following aspiration of its contents and after removal of the right sublingual and mandibular salivary glands. The lateral midcervical location of the mass and the serous nature of the fluid within the mass were inconsistent with a salivary mucocele. Excisional biopsy was curative and revealed an intestinal choristoma.     

Histo-ontogenetic study of the parotid salivary gland of Indian buffalo

The present study was aimed at elucidating the histogenesis of parotid gland of buffalo. The study was carried out on buffalo foetuses (n = 36), during different stages of prenatal life. The foetuses were categorised into three groups based on their curved crown rump length (CVRL). The primordial anlage of parotid salivary gland was evident at 40th day of development whereas the primary ducts, in the form of cords, were first observed at 81st day of prenatal life. The capsule formation as well as the lobulation of the gland was initiated at 127th day. At 141st day, the duct system of gland was completed. The terminal tubules attained the structure of acini at 167th day. The myoepithelial cells first appeared as flattened basal cells initially around the developing acinar cells at 167th day. The typical compound tubulo-acinar nature of the gland was first observed at 185th day. Purely serous acinar cells were seen from 185th day onwards. The micrometrical studies revealed that the mean diameter of acinar cells, intercalated ducts, striated ducts and large ducts increased with the advancement of age. The serous acinar cells were devoid of acidic as well as neutral mucopolysaccharides in prenatal age groups; however, large ducts with goblet cells exhibited positive reaction. Combined PAS-AB method revealed mixed reaction in acinar cells as well as in large ducts. Fine lipid droplets were observed in intralobular as well as interlobular connective tissue; however, phospholipids were observed in the cell membrane of secretory cells and ducts.     

Histological Structure and Distribution of Carbonic Anhydrase Isozymes (CA‐I,II, III and VI) in Major Salivary Glands in Koalas

While the mandibular glands usually consist of only mucous acinar cells or a combination of mucous and serous cells in other species of mammals, those of koalas were serous glands. Rabbit mono‐specific polyclonal anti‐canine CA‐I, II, III or VI antiserum showed cross‐reactivity against corresponding koala carbonic anhydrase (CA) isozymes. Although immunohistochemical reactions to CA‐I, II and VI in ductal cells were moderate to strong in the tested salivary glands, no reaction or only slight reactions were observed against CA‐III. In the sublingual glands, moderate immunohistochemical reactions to CA‐I, II and VI were also evident in serous acinar cells and serous demilunes. However, no reactions to the tested isozymes were observed in mucous acinar cells in these glands. With the exception of the histological structure of the mandibular glands, histological features and the distributional profile of CA isozymes of the salivary glands in koalas are relatively close to results obtained from horses.     

Ultrastructure of the platypus and echidna mandibular glands

The secretory units of the platypus and echidna mandibular glands consist of a single serous cell type. Secretory granules within the cells of the platypus mandibular gland stained intensely with the periodic acid-Schiff staining procedure but failed to stain with Alcian Blue, suggesting the granules contained neutral glycoproteins. Secretory granules within the mandibular glands of the echidna failed to stain with the methods used indicating little if any glycoprotein was associated with the secretory granules. Ultrastructurally, secretory granules of the platypus mandibular gland were electron dense with a central core of less electron-dense material and were membrane bound. In contrast, those of the echidna presented a lamellated appearance and also were limited by a membrane. These secretory granules appeared to form as a result of concentric layering of lamellae within cisternae of the Golgi membranes. The intralobular ductal system of the platypus was more extensively developed than that of the echidna. The striated ducts of both species were characterized by elaborate infoldings of the basolateral plasmalemma and an abundance of associated mitochondria.     

Ultrastructural study of sheep lacrimal glands.

Sheep lacrimal glands are mixed glands, consisting of tubulo-acinar units succeeded by ducts of simple morphology. The secretory portions consist of three cell types: mucous, seromucous and serous, which may be intermingled in the same acinus or may form acini wholly made of only serous or mucous cells. Mucous cells show a rough endoplasmic reticulum that is reduced to a few cisternae located near the cell base and among the interstices of the secretory droplets. Mucous granules appear uniformly electron-lucent. Serous cells display a typical structure; serous granules can be uniformly electron-dense or composed of dense inclusions dispersed in an electron-lucent matrix. The seromucous granules have a bizonal substructure: a dense core is embedded in a highter matrix. Secretory acini are succeeded by intercalated ducts; the epithelium of these ducts gradually increases in height to form a kind of excretory duct, without the intervention of striated ducts.     

Metaplastic ossification of a cervical sialocoele in a dog

Metaplastic ossification of a long-standing cervical sialocoele was identified in a 2-year-old male Hellenic Hound dog. Diagnosis was based upon history, clinical findings, paracentesis and histopathology. Trauma or chronic inflammation of the mandibular gland/duct complex were the most probable causes of the ossification. Surgical excision of the ossified mass, as well as of mandibular and sublingual salivary glands/ducts of the affected side, resulted in clinical remission.