Franzén L, Gustafsson H, Sundström S, Karlsson M, Littbrand B, Henriksson R
Department of Oncology, Otorhinolaryngology, Histology and Cell Biology, University Hospital, Umea, Sweden.
Int J Radiat Biol. 1993 Jul;64(1):93-101. doi: 10.1080/09553009314551141.
Irradiation of head- and neck cancer commonly results in oral dryness and discomfort for the patients due to salivary gland damage. The exact mechanisms behind the inherent radiosensitivity of salivary glands remain to be elucidated. In the present study, we used different in vitro secretory models and quantitative morphological characterization of rat parotid gland following fractionated unilateral irradiation to one gland on a 5-day fraction schedule (Monday-Friday) with 6 MV photons (total dose 30, 35, 40 and 45 Gy) or a two-fractions regimens in 5 days (Monday and Friday) with total dose of 24 and 32 Gy. The contralateral shielded gland served as control, and parallel analyses of irradiated and control glands were performed 180 days following the last irradiation treatment. The relative noradrenaline stimulated electrolyte secretion (86rubidium tracer for potassium) was decreased in the irradiated compared with control glands. The noradrenaline-stimulated exocytotic amylase release was not significantly affected by irradiation, but the gland content of amylase was decreased dose-dependently. The quantitative morphological analysis revealed a dose-dependent decline in the number of acinar cells, whereas the other parenchymal cells (intercalated, striated- and excretory duct cells) were unaffected by the irradiation compared with control glands.
头颈癌放疗通常会因唾液腺损伤而导致患者口腔干燥和不适。唾液腺固有放射敏感性背后的确切机制仍有待阐明。在本研究中，我们使用了不同的体外分泌模型，并对大鼠腮腺进行了定量形态学表征。将大鼠一侧腮腺在5天内（周一至周五）进行分次单侧照射，采用6兆伏光子（总剂量分别为30、35、40和45戈瑞），或在5天内分两次照射（周一和周五），总剂量为24和32戈瑞。对侧屏蔽的腺体作为对照，在最后一次照射治疗180天后，对照射腺体和对照腺体进行平行分析。与对照腺体相比，照射腺体中去甲肾上腺素刺激的电解质分泌（用86铷示踪钾）减少。去甲肾上腺素刺激的淀粉酶胞吐释放未受到照射的显著影响，但淀粉酶的腺体含量呈剂量依赖性降低。定量形态学分析显示，腺泡细胞数量呈剂量依赖性减少，而与对照腺体相比，其他实质细胞（闰管、纹状管和排泄管细胞）未受照射影响。
