辐射对豚鼠鼻黏膜组织结构及微血管的影响

目的：探讨辐射对豚鼠鼻黏膜结构及微血管的损伤。方法：选择健康豚鼠84只，随机分为对照组（12只）及照射组（72只）。均在同样条件下喂养。将照射组豚鼠置于直线加速器射线内照射，每周1次，每次照射5Gy，计3周，总剂量15Gy，建立辐射损伤动物模型。分别于照射后0．5、1.0、2．0、3．0、5．0、6．0个月处死动物12只，随机取6只做鼻腔黏膜微血管铸型，另6只做病理检查。对照组在假照射后6个月处死动物，随机各选6只分别做鼻黏膜微血管铸型检查和病理检查。结果：照射组豚鼠的鼻黏膜辐射后早期表现为急性炎症反应，黏膜大量坏死、脱落，电镜下见仅少部分黏膜表面还被覆着正常的纤毛结构。以后黏膜开始修复，至6个月时基本结束，但大部分黏膜失去了正常的纤毛柱状上皮结构特点，部分区域甚至代为组织转化的鳞状上皮；微血管铸型可见，早期改变为毛细血管扩张充血及血管内皮细胞肿胀，以后逐渐出现毛细血管的扭曲变形、闭塞及中断，毛细血管数量大量减少，致血液回流障碍，微静脉萎瘪。后期部分区域出现新生的毛细血管，但结构紊乱，不具备微循环的功能。结论：鼻黏膜的损伤、晚期的鳞状上皮组织转化以及鼻黏膜微循环的破坏是放疗后鼻腔功能障碍的病理学基础。

Effect of radiation on nasal mucosa and the microvascular casting of guinea pig

Objective:To study the histopathologic and microvascular changes in nasal mucosa of guinea pigs following a series of irradiation.Method:A total of 84 healthy guinea pig were divided into two groups randomly :the irradiation group(n=72) and the control group(n=12).The animals of the irradiation group were exposed nasally to linear accelerator X-rays at 5.0 Gy once a week for three weeks .At 0.5,1,2,3,5,6 month after X-irradiation 12 animals from each group were sacrificed at each time point. The animals of control group did not be irradiated and were sacrificed after 6 month. Their middle nasal turbinate mucosa of 6 animals from each group was observed under optical microscope and scanning electron microscope and the another 6 animals was made microvascular corrosion casts.Result:In the irradiation group,the early histopathologicsl transformation was acute inflammatory reaction, nasal mucosa tissues congesting, partial nasal mucosa necrosis or shedding. The inflammation cells infiltrated into the submucosa. The acute inflammatory reaction declined as the time went by. Then the nasal mucosa repaired step by step. But parts of the area were squamous epithelium instead of the normal ciliary structure. Through scanning electron microscope, we found the capillary of nasal mucosa expanded and congested, the vascular endothelial cell swelled. As the time went by, the capillary became deformation and tore and the microvascular networks broke off. All changes which led to capillary density descended. Although partial area had new capillary, but the structure was disordered and had no microcirculation function.Conclusion:The nasal mucosa injury, the squamous metaplasia and the microvascular networks broke off can form a pathological basis of dysfunction after irradiation.