Objectives The aim of this research was to study the intensity of cytokeratin 17 (CK17) in the parenchymal elements of rat’s submandibular salivary glands subjected to fractionated radiotherapy regimen that used for treatment of head and neck malignancy. Materials and Methods Twenty male albino rats were divided into two equal groups (normal and irradiated). The irradiated group received a radiation dose of 5 Grays daily for 5 days using therapeutic X-ray beam. Six months later, submandibular gland was dissected out and prepared for both histological and immunohistochemical studies. Results Submandibular gland of irradiated group showed two different types of histological alterations. The first alteration showed severe gland atrophy replaced by either fibrous or fatty tissues. In some sections, the gland exhibited proliferating activity in the form of profuse amounts of mitotic figures. Immunohistochemical examination of control glands displayed a mild cytoplasmic expression of CK17 of duct cells as well as serous acini. The staining pattern was either diffused or concentrated at the basal part of the cell with negative expression at its apical part. Statistical Analysis Expression of CK17 in submandibular gland of irradiated group displayed a highly significant differences (P < 0.001) in both intercalated and striated ducts. Many serous acini displayed a highly significant differences (P < 0.001) whereas, mucous acini were negatively stained. Conclusions The intensity and diffusion of CK17 expression in our results foretell the pathological effect of radiotherapy on the intermediate filaments of salivary gland parenchyma that interfered with production and/or secretion of saliva leading to xerostomia.

Objectives The present study aimed to give a glimpse of the normal distribution of intermediate filaments within the parotid gland parenchyma of mongrel dogs and to reveal the pathological changes that may occur as a result of the effects of diabetes mellitus or atrophy of the gland caused by the ligation of the excretory duct to discover whether there is a similarity in these pathological behaviors. Materials and Methods Twelve healthy mongrel dogs were used in the experiment and were divided into three groups: group I (the control group), group II (dogs with alloxan-induced diabetes), and group III (dogs with the right-side duct-ligated parotid gland). The dogs were sacrificed 45 days after the parotid excretory duct were tied. The right parotid gland of all groups was dissected and prepared for histological and immunohistochemical expression of cytokeratin 17 assay. Results Histological findings confirmed that the parotid gland parenchyma of the diabetic group had glandular atrophy characterized by the loss of gland structure, degenerated acini, and dilatation of the duct system. Moreover, there is a predominance of the fibrous component with the presence of fat cells within the gland compartments. On the contrary, the excretory duct-ligated group undergoes severe glandular atrophy of the previous character with the presence of duct-like structure as well as extravasation and vasodilatation. Immunohistochemical expression of cytokeratin 17 in control parotid using an immunoperoxidase technique showed that cytokeratin expression varies from negative to mild in all ducts and some serous acinar cells. The gland parenchyma of the diabetic group showed mild to strong cytokeratin expression of duct cells more concentrated in the apical part with moderate to strong expression of diffuse type in some serous acini. The intensity of cytokeratin 17 in gland compartments of the excretory duct-ligated group revealed a variation in expression that ranged from negative to strong diffuse staining throughout the gland. Conclusion The severity and prevalence of cytokeratin 17 in our results are predictive of the pathological influence of both diabetes mellitus and duct ligation on the cytokeratin intracellular filaments of the salivary gland parenchyma in a different way that interferes with saliva production and/or secretion leading to xerostomia.

Objectives Diabetes mellitus (DM) is a notorious chronic disease characterized by hyperglycemia. Our study aimed to determine the expression of cytokeratin 17 (CK17) in all major salivary glands of diabetic albino rats to provide more information about the pathological effects of DM on the intracellular structures of the gland parenchyma. Method Twenty male adult albino rats were utilized in the experiment and divided into two equal groups, group 1 (control rats) and group 2 (diabetic rats). The animals were sacrificed 45 days after diabetes induction. The major salivary gland complex of all groups was dissected and prepared for evaluation by histological and immunohistochemical expression of CK17. Results Histological results prove that the salivary gland parenchyma of diabetic group undergo gland atrophy characterized with the presence of degenerated acini, dilated duct system, and presence of duct-like structure with predominance of fibrous tissue compartment and discrete fat cells. Immunohistochemical expression of CK17 of major salivary gland of control group revealed negative to diffuse mild expression in all duct cells and some serous acinar cells, whereas mucous acini were negatively stained. On the other hand, major salivary gland parenchyma of diabetic group demonstrated mild to strong expression of duct cells more concentrated at their apical part with moderate to strong expression of some serous acini of diffuse type, whereas mucous acini of both submandibular gland and sublingual gland (SLG) were negatively stained. Conclusion The severity and prevalence of CK 17 in our results are predictive of the pathological influence of the DM that interferes with saliva production and/or secretion leading to dry mouth. Also, SLG of diabetic rats showed inspiratory changes in immunohistochemical expression in CK17 in spite of they did not show an effect of lesser degree in the routine hematoxylin and eosin histological study.

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