Abstract
<jats:p>The ductal system of the salivary glands not only ensures saliva transport but also participates in its formation and modification; therefore, alterations in its structural parameters may impair salivary secretion. The aim of the study was to determine the dynamics of morphometric parameters of the intercalated, striated, granular, and intralobular collecting ducts of the submandibular salivary glands in rats under normal conditions and following the combined action of food additives. The study was performed on 84 sexually mature male rats. Animals of the control group received drinking water and physiological saline, whereas rats of the experimental group were administered 0.6 mg/kg sodium nitrite, 20 mg/kg monosodium glutamate, and 5 mg/kg Ponceau 4R in 0.5 mL of distilled water orally once daily. The animals were removed from the experiment after 1, 4, 8, 12, and 16 weeks. Fragments of the glands were fixed in 10 % neutral formalin and glutaraldehyde and embedded in paraffin and Epon-812. Microphotography and morphometric analysis were performed using a Levenhuk D740T digital microscope, and statistical processing was carried out in Excel. In the intercalated ducts, a significant decrease in the outer diameter, lumen diameter, and epithelial cell height was observed as early as week 1, and by week 16 these parameters remained lower than the control values. At the initial stages of the experiment, the striated ducts responded with an increase in outer diameter, lumen diameter, and epithelial cell height; however, subsequent narrowing of the lumen and a decrease in some parameters were observed. In the granular ducts, an increase in the outer diameter and epithelial cell height predominated up to week 12, whereas by week 16 the epithelial cell height decreased below the control level. The intralobular collecting ducts were characterized by an early increase in morphometric parameters followed by a decrease in lumen diameter and epithelial cell height at later stages. The obtained data indicate wave-like remodeling of the ductal system, in which early compensatory-adaptive responses were replaced by signs of dystrophic alterations. The identified morphological changes indicate impairment of the functional state of the ductal system and disturbances in the processes of saliva formation, transport, and modification.</jats:p>