Hassan Sherif S, Attia Mahmoud A, Attia Alaa M, Nofal Reda A, Fathi Adel
Department of Oral Biology and Dental Anatomy, Faculty of Dentistry, Al-Azhar University (Assiut), Egypt and, Umm Al-Qura University, Saudi Arabia.
Department of Oral Pathology, Faculty of Dentistry, Al-Azhar University, (Assiut), Egypt and Faculty of Applied Medical Science, Al-Baha University, Saudi Arabia.
Eur J Dent. 2020 Jul;14(3):440-447. doi: 10.1055/s-0040-1713705. Epub 2020 Jun 26.
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.
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.
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.
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.
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.
本研究旨在探讨用于治疗头颈部恶性肿瘤的分次放疗方案对大鼠下颌下唾液腺实质细胞角蛋白17（CK17）表达强度的影响。
将20只雄性白化大鼠分为两组（正常组和照射组），每组10只。照射组使用治疗性X射线束，每天给予5格雷的辐射剂量，连续照射5天。6个月后，取出下颌下腺，进行组织学和免疫组织化学研究。
照射组下颌下腺出现两种不同类型的组织学改变。第一种改变表现为严重的腺体萎缩，被纤维组织或脂肪组织取代。在一些切片中，腺体呈现出大量有丝分裂象的增殖活性。对照组腺体的免疫组织化学检查显示，导管细胞和浆液性腺泡的CK17呈轻度细胞质表达。染色模式为弥漫性或集中在细胞基部，顶端部分呈阴性表达。
照射组下颌下腺闰管和纹状管中CK17的表达存在高度显著差异（P < 0.001）。许多浆液性腺泡也存在高度显著差异（P < 0.001），而黏液性腺泡呈阴性染色。
我们的研究结果显示，CK17表达的强度和分布预示了放疗对唾液腺实质中间丝的病理影响，这种影响干扰了唾液的产生和/或分泌，导致口干症。
