IntroductionSalivary alpha‐amylase is one of the major enzymes in the oral cavity. Beyond its primary function of initiation of digestion in the oral cavity, it is involved in defense against bacteria. Alpha‐amylase, a product of serous cells, is the most abundant protein of parotid saliva and it is also secreted by sublingual glands. However, its presence in the minor glands, including palatine glands, has been contradictory. Therefore, this study was conducted to observe the expression of alpha‐amylase at different developmental stages of rat palatine glands using light microscopic immunohistochemistry.Materials and MethodsAn avidin‐biotin technique was used to detect the binding of alpha‐amylase on sagittal frozen sections of palatine glands of pre‐ and post‐natal rats.ResultsPositive reaction of alpha‐amylase was observed at the basolateral and perinuclear membranes of the developing acinar cells at the embryonic day 20 (E20). At birth, in addition to the basolateral membranes, weak cytoplasmic reaction labelling a few mucous cells was observed. Amylase reactivity increased with maturation and reached peak reactivity at postnatal day (PN) 10 and 14, thereafter, decreased into adulthood. Serous cells expressed amylase starting from PN7. Whereas ducts showed variable reaction on the luminal membrane starting from PN3. In adult rats, heterogeneous distribution was revealed between the anterior and posterior portions of palatine glands, as amylase showed more reactivity in the posterior portion.ConclusionThe expression and distribution of alpha‐amylase showed significant modifications during cytodifferentiation and maturation of the palatine glands.Support or Funding InformationNoneThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.