Tubuloalveolar Glands Research Articles

Anatomical, histological and histochemical observations and changes in the poll glands of the camel (<i>Camelus dromedarius</i>)

This study deals with the anatomical, histological and histochemical observations and the changes in the poll glands due to age, seasonal variations and castration. The male camels had two poll glands, one on either side of the mid-line of the poll region. The glands were present in the male camels at birth, while no visible glands were observed in the she-camels at any age. The weight and dimensions of the glands increased with age in the uncastrated camels, but the glands regressed after castration. The active glands were compound tubulo-alveolar glands. The tubules and alveoli were lined by simple squamous to high cuboidal epithelium depending on the secretory stages. The mild PAS-reactive apical blebs of the secretory cells were also positive for acid mucopolysaccharides and alkaline phosphatase. The myoepithelial cells around the alveoli and small ducts were PAS-negative. The intralobular ducts were lined by simple cuboidal epithelium. The stratified cuboidal epithelium lining the initial portion of the excretory duct abruptly changed into the stratified squamous epithelium which continued with the cutaneous epithelium of the skin. The ducts opened into the neck of the hair follicles above the level of the sebaceous ducts. The glands appeared to be modified apocrine sweat glands in the histological appearance. The interglandular connective tissue was reduced to thin strands during the winter months while, comparatively, in the summer months, the connective tissue increased. During the winter months of December to March the pungent coffee-coloured secretion from the glands was most profusing in those camels who were apparently in rut. The tubules and alveoli in such glands were lined by high cuboidal cells with apical blebs. During the summer months, the secretion was scanty except in severe exercises, and the glandular epithelium varied from simple squamous to low cuboidal.

Lincomycin-Induced Cholecystitis and Gallstones in Guinea Pigs

Guinea pigs given lincomycin 60 mg per kg per day showed a striking increase in the renewal of epithelial cells in the gallbladder. This was detectable after only 24 hr of treatment. By 48 hr a precipitate consisting predominantly of calcium and bilirubin had formed in the gallbladder. Gallbladder bile glycoprotein concentrations rose progressively. At 8 days epithelial dysplasia was marked. Treatment was discontinued at 9 days. The guinea pigs that survived beyond 34 days showed that new tubuloalveolar glands had formed focally in the body and fundus of the gallbladder. Multiple calcium-containing stones were present. The failure to culture bacteria from bile, the failure of the bile salt pattern to change, and the progressive nature of the epithelial injury suggested that the changes resulted from a direct toxic effect and were not dependent on the antibiotic activity of this drug. It was concluded that damage to the epithelium of the gallbladder preceded the formation of a precipitate and initiated histological changes which culminated, at the time that the precipitate became organized into stones, in impressive glandular metaplasia.

Macroscopic and microscopic study of the mandibular salivary gland of Black Bengal goats

The gross anatomy and microscopic structures of the mandibular salivary gland of 15 Black Bengal goats of either sex and different ages were carried out during the period from January 1999 to December 2000. The mandibular salivary gland was irregularly triangular in shape and was situated ventral and caudal part of the angle of the mandible and partly covered by the ventral part of the parotid gland. The gland was cream colored in fresh condition and the lobules were coarser and less compact in texture. The   mandibular duct left the gland near the middle of the cranio-dorsal border and opened into the caruncula sublingualis with the sublingual duct in common. The average length of the duct was 11 cm. The branches of external carotid, lingual and occipital arteries supplied the mandibular salivary gland. The mandibular gland was drained by the lingofacial and lingiual veins and occasionally by the laryngeal vein. It was mixed tubulo-alveolar gland and consisted to numerous lobes and lobules; supported by connective tissue capsule. The mixed alveoli were more than the isolated serous and mucous alveoli.Key words: Mandibular salivary gland; macroscopic, microscopic; Black Bengal goatsdoi: 10.3329/bjvm.v2i2.2556Bangl. J. Vet. Med. (2004). 2 (2): 137-142