HISTOLOGICAL AND HISTOCHEMICAL EVALUATION OF LINGUAL SALIVARY GLANDS IN WISTAR RATS

Lingual salivary glands are exocrine glands responsible for the production of saliva.From those, von Ebner's glands, located in the vicinity of the taste buds, and Weber's glands, present in the root of the tongue can be mentioned. The aim of the present study was to evaluate the minor salivary glands located in the Wistar rat's tongue in order to obtain detailed information about their structure and function. Tongue samples from 5 rats were harvested, fixed in 10% buffered formalin,and processed according to the classical histological technique. In order to evidentiate several aspects, we used three different staining methods: Goldner's trichrome and two histochemical special stainings, namely Periodic Acid Schiff (PAS) and Alcian Blue. The results obtained suggested that Weber's gland presents different morphological features as compared with von Ebner's gland. The acinar cells of the von Ebner's gland showed an Alcian negative but a PAS-positive reaction. Moreover, the morphological aspect of the cytoplasm suggests that the secretion does not contain neutral mucins, but other types of PAS-positive substances. Contrariwise, the acinar cells in Weber's gland synthesize both neutral mucins, highlighted by the PAS reaction, and acidic mucins, highlighted by staining with Alcian blue. Besides, from a quantitative point of view, the neutral mucins surpass the acidic ones. The two glands present several differences from a morphological, but also from a functional point of view. Knowing the type and intensity of lingual salivary gland secretion is very important, especially in species that are frequently used as research models, such as the Wistar rat.