TNF-α在中子及γ线照射小鼠肠组织中的表达

目的:比较小鼠经中子及γ线照射后,肠组织中TNF-α的表达及其意义。方法:350只二级雄性BALB/c小鼠,经不同剂量的中子和γ线照射,于照后6、12h,1、2、3、4、5、7、10、14、21、28d分批活杀,采用免疫组化染色等技术观察TNF-α在肠组织中的变化。结果:在正常肠黏膜中,TNF-α主要见于肠绒毛间质、黏膜下及淋巴组织中巨噬细胞浆内;2.5Gy中子照后2d内,上述阳性部位TNF-α的表达进行性减少;3~7d其在巨噬细胞及隐窝细胞浆内的表达明显增加,5d达高峰,14d恢复至正常水平。4.0、5.5Gy中子及12Gyγ线照射后4d内,TNF-α的表达进行性减少;γ线5.5Gy照后6~12h,TNF-α的表达增多,照后1d减少,2~5d增加,3d达高峰,10d恢复至正常水平。TNF-α的表达在肠黏膜损伤时减少,于损伤后恢复的早期增多。结论:中子和γ线照后,肠内源性TNF-α表达具有不同的变化规律,并参与了肠放射损伤及修复的病理生理过程。

The expression of TNF-α in the intestine of mice irradiated by neutron and γ rays

AIM: To study the expression of tumor necrosis factor alpha (TNF-alpha) in the intestine of mice irradiated by neutron and gamma rays. METHODS: 350 male BALB/c mice were irradiated with neutron and gamma rays of different doses, and sacrificed at 6 and 12 hours, 1, 2, 3, 4, 5, 7, 10, 14, 21 and 28 days after irradiation. The TNF-alpha in the mice intestinal tissue was detected by means of immunohistochemical staining and image analysis. RESULTS: In normal control mice, TNF-alpha was expressed in the cytoplasm of macrophages in intestinal villus interstitium, submucosa and lymph tissue. After 2.5Gy neutron radiation, TNF-alpha was decreased progressively within 2 days, increased obviously in macrophages and crypt cells during the 3rd-7th day, reached the peak at the 5th day and recovered to normal level at the 14th day. TNF-alpha was decreased progressively within 4 days after 4.0 and 5.5Gy neutron and 12Gy gamma ray irradiation. TNF-gamma was increased obviously in 6-12 hours, decreased on the first day, increased at the 2nd-5th day, peaked at the third day and recovered at the 10th day after 5.5Gy gamma ray irradiation. CONCLUSION: Neutron and gamma ray radiation induce different expression profile of endogenous TNF-gamma in small intestine, which may be related with the pathologic courses of irradiation-induced damage and repair of intestine.