γ射线照射对小鼠肠道黏膜上皮细胞增殖的影响

发布时间：2018-06-05 23:56

本文选题：照射 + 肠道　；参考：《南昌大学》2012年硕士论文

【摘要】：目的：观察不同剂量γ射线照射后小鼠空肠、回肠和结肠的形态学变化，肠粘膜上皮内BrdU、Ki67免疫反应阳性增殖细胞的分布和数量变化的规律，肠绒毛及肠腺β-catenin蛋白表达量的变化，以了解γ射线照射后肠道的损伤程度及肠粘膜上皮细胞系的增殖状态，从而探讨射线照射对肠道上皮增殖细胞的影响，肠道上皮增殖细胞在肠黏膜损伤及修复的作用及可能机制，为进一步研究放射性肠道损伤提供实验依据。方法：雄性C57BL/6小鼠72只，随机分为正常对照组、4Gy、8Gy、15Gy照射组四组。以60Coγ射线全身一次性照射制作动物模型，各组分别在1天，3天，5天称重并处死小鼠。各小鼠处死前2个小时腹腔注射BrdU(120mg/kg体重)。取空肠、回肠、结肠于4%多聚甲醛液中固定，石蜡包埋、切片。常规HE染色后观察肠道组织病理学变化并测量空肠、回肠肠绒毛高度和肠腺深度；免疫组化法检测肠道BrdU、Ki67阳性细胞及β-catenin表达，并通过图像分析系统拍照后进行相关体视学分析，测算各肠段粘膜上皮内BrdU、Ki67阳性细胞的数密度；肠绒毛及肠腺β-catenin蛋白的平均光密度。用统计软件SPSS17.0比较各组参数的差异。结果：1．8Gy、15Gy中、高剂量γ射线照射可致小鼠精神不振，进食量减少，体重减轻；15Gy照射后4天内受照射小鼠全部死亡。 2．不同剂量照射后小鼠肠黏膜组织均出现不同程度的损伤。损伤程度可随剂量增加而加重，其中15Gy照射组3天损伤最为严重，4Gy、8Gy第3天肠道损伤明显，至第5天损伤有所恢复。回肠段损伤比其他肠段严重。形态测量学显示，受γ射线照射后，绒毛变矮，肠腺变浅。 3．正常情况下，BrdU阳性细胞的数密度回肠空肠结肠；受γ射线照射后，各肠段BrdU阳性细胞的数密度随照射剂量增加而降低，在照射后的第1天，低剂量照射便可见明显降低，各剂量组各部位（除结肠4Gy组外）均明显低于正常对照组（均P＜0.01）；随照射后时间延长，4Gy组和8Gy组各部位BrdU阳性细胞的数密度逐渐回升，5天时4Gy组恢复至接近正常水平，但15Gy组随时间延长而显著降低。 4．正常情况下，Ki67阳性细胞数密度绒毛肠腺，回肠绒毛空肠绒毛，空肠肠腺结肠肠腺回肠肠腺；受γ射线照射后，各肠段绒毛和/或肠腺Ki67阳性细胞的数密度随照射剂量增加而降低，对肠腺的影响程度高于对绒毛的影响程度；照射后1天的数据比较，低剂量照射Ki67阳性细胞的数密度便明显降低，各剂量组各部位（除回肠肠腺外）均明显低于正常对照组（均P＜0.01）；随照射后时间延长，4Gy组和8Gy组各部位Ki67阳性细胞的数密度逐渐回升，，5天时4Gy组恢复至接近正常水平，但15Gy组随时间延长而显著降低。肠绒毛和肠腺Ki67阳性细胞数密度与绒毛高度和肠腺深度呈正相关。 5．正常小鼠肠腺β-catenin可表达于上皮细胞胞膜、胞质和细胞核，照射组仅位于胞膜、胞质，细胞核没有表达。正常情况下，β-catenin的平均光密度肠腺绒毛，空肠绒毛回肠绒毛，空肠肠腺回肠肠腺结肠肠腺；各肠段绒毛和/或肠腺β-catenin平均光密度随照射剂量增加而降低，对肠腺的影响程度高于对绒毛的影响程度，以照射后1天最明显（均P＜0.01），随照射后时间延长，4Gy组和8Gy组各部位β-catenin平均光密度逐渐回升，4Gy组5天恢复至接近正常水平，但15Gy组随时间延长而显著降低。结论：1．不同剂量γ射线照射可引起小鼠肠粘膜不同程度损伤，即剂量越大，损伤越严重。 2．不同剂量γ射线照射后小鼠肠腺BrdU，肠腺、肠绒毛Ki67阳性细胞数量及β-catenin蛋白表达均明显降低，表明照射可影响肠道细胞增殖。肠道增殖细胞的数量与肠绒毛高度和肠腺深度变化呈正相关。 3．小剂量和中剂量γ射线照射后，随时间延长肠道损伤、肠上皮增殖细胞的数量及β-catenin蛋白表达可逐渐修复。
[Abstract]:Objective : To observe the morphological changes of jejunum , ileum and colon of mice after irradiation with different doses of 纬 - rays , the changes of the distribution and quantity of the positive proliferating cells in the intestinal mucosa , the changes of the expression of 尾 - catenin in the intestinal mucosa , the effect of radiation on the intestinal epithelial proliferation cells , the role of intestinal epithelial proliferation cells in intestinal mucosa injury and repair , and the possible mechanism to provide experimental basis for further study of radiation intestinal injury .

Methods : 72 male C57BL / 6 mice were randomly divided into four groups : normal control group , 4Gy , 8Gy and 15Gy irradiation group .
Immunohistochemical method was used to detect the expression of the positive cells and 尾 - catenin in intestinal tract of intestinal tract . After taking pictures by the image analysis system , the relative stereology analysis was carried out to measure the number density of the positive cells in the intestinal mucosa of the intestinal segments .
The average optical density of 尾 - catenin in intestinal villi and intestinal gland was compared with SPSS 17.0 .

Results : 1 . 8 Gy , 15 Gy , high - dose 纬 - ray irradiation could cause the mice to be depressed , the consumption of food decreased , and the weight loss was reduced ;
All mice died within 4 days after 15 Gy irradiation .

2 . Different degrees of damage were observed in intestinal mucosal tissues of mice after irradiation with different doses . The degree of injury could be increased with increasing dose , in which 15 Gy irradiation group was most severely damaged in 3 days , 4 Gy , 8 Gy group 3 intestinal injury was obvious , and the injury on the fifth day was recovered . The injury of ileum was more serious than that of other intestinal segments .

3 . In the normal condition , the number density of the positive cells was ileum jejunum colon .
After irradiation with 纬 - rays , the number density decreased with the increase of irradiation dose . After irradiation , low dose irradiation was significantly lower than that in normal control group ( P < 0.01 ) .
At the time of irradiation , the number density gradually increased at 4 Gy group and 8 Gy group , and 4 Gy group recovered to near normal level at 5 days , but the 15 Gy group was significantly decreased with time .

4 . Under normal conditions , the positive cells of Ki - 67 positive cells were in the form of intestinal gland , ileum villi , ileum and ileum .
After 纬 - ray irradiation , the number density of the positive cells in the villi and / or the intestinal gland of the intestinal segments decreased with the increase of the irradiation dose , and the degree of influence on the intestinal gland was higher than that of the villi .
Compared with the normal control group ( P & lt ; 0.01 ) , the data of 1 day after irradiation was lower than that of the normal control group ( P < 0.01 ) .
The number density of Ki - 67 positive cells in 4 Gy group and 8 Gy group increased gradually with the time of irradiation , and the 4 Gy group recovered to near normal level at 5 days , but the 15 Gy group was significantly decreased with time . The density of positive cells in intestinal villi and intestinal gland was positively correlated with the height of villi and the depth of intestinal gland .

5 . 尾 - catenin was expressed in the membrane , cytoplasm and nucleus of epithelial cells in normal mice .
The average optical density of 尾 - catenin in the villi and / or intestinal gland of each intestinal segment decreased with increasing irradiation dose , and the influence degree on the intestinal gland was higher than that of the villi . The average optical density of 尾 - catenin in each part of the 4Gy group and the 8Gy group increased gradually after irradiation .

Conclusion : 1 . Gamma - ray irradiation at different doses can cause different degrees of damage to the intestinal mucosa of mice , that is , the greater the dose , the more severe the injury .

2 . The number of cells and the expression of 尾 - catenin in the intestinal gland of mice were significantly decreased after irradiation with different doses of 纬 - rays , indicating that the irradiation could affect the proliferation of intestinal cells . The number of intestinal proliferation cells was positively correlated with the height of the intestinal villi and the depth of the intestinal gland .

3 . After irradiation with low - dose and medium - dose gamma - rays , the number of intestinal epithelial proliferation cells and the expression of 尾 - catenin protein can be gradually repaired with time prolonging the intestinal injury .
【学位授予单位】：南昌大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R363

【参考文献】