Comparative histological and histochemical analysis of the minor salivary glands in porcine species

The present work explored the anatomical distribution, histology, and histochemistry of minor salivary glands in pigs during postnatal life. Heads from ten healthy adult pigs were procured from a local slaughterhouse immediately after decapitation for fresh tissue collection. Histologically, glands were located in the propria-submucosa of the oral mucosa. Secretory acini were mucous, serous, or mixed depending on location, with serous demilunes observed peripherally to mucous units. Myoepithelial cells were present between secretory cell bases and the basal lamina. The duct system comprised intralobular and interlobular ducts. Intercalated ducts had small lumens and a simple cuboidal lining. Striated ducts were lined by simple to stratified columnar epithelium (one to two cells thick) with characteristic basal longitudinal striations. Large interlobular ducts within interlobular septae were lined by stratified columnar epithelium and contained goblet cells. Histochemistry revealed weakly acidic sulfated mucosubstances, sialomucins, glycogen, mucopolysaccharides, mucin, and protein in mucous units, while serous acini and ducts were negative for these moieties. Morphometrically, the acinar and luminal diameters of mucous acini exceeded those of serous acini. Interlobular duct diameter was significantly larger than that of intercalated and striated ducts (p < 0.01 and p < 0.05). This work provides a novel, detailed baseline of the normal anatomy and histochemistry of porcine minor salivary glands. Its relevance is twofold: it establishes the pig as a valuable model for salivary gland research due to its structural similarities to humans, and it supplies essential morphological data to inform accurate surgical intervention and pathological diagnosis of glandular affections in both veterinary and comparative medical contexts.