中子及γ射线照射对小鼠肠道EGF及EGFR表达的影响

Studies on the effects of EGF and EGFR on the injury of mice intestines induced by neutron and γ-ray irradiation

目的研究小鼠经中子及γ射线照射后肠组织中EGF和EGFR的表达变化及其意义。方法350只二级雄性BALB/C小鼠,经不同剂量的中子和γ射线照射,于照后6h、12h及1、2、3、4、5、7、10、14、21、28天分批活杀,采用免疫组化法研究EGF和EG-FR在肠组织中的变化。结果肠黏膜上皮和隐窝细胞浆内EGF及EGFR表达在2·5Gy中子照后1天内增强,1~2天减少,3~7天增多,5天达高峰,14天后恢复至正常水平;4·0、5·5Gy中子及12Gyγ射线照射后6h增多,12h^4天进行性减少;5·5Gyγ射线照射后3天内增加,3天达高峰,5天后逐渐恢复。结论中子和γ射线照射后肠内源性EGF及EGFR的表达具有不同的变化规律,参与了肠放射损伤及修复的病理过程。

Objective To study comparatively the changes in epithelial growth factor （EGF） and its receptor （EGFR） in injured intestine induced by neutron and γ-ray irradiation in mice and their significance. Methods 350 male BALB/C mice were irradiated with neutron and γ-rays, and they were sacrificed at 6 and 12 hours and 1, 2, 3, 4, 5, 7, 10, 14, 21 and 28 days, respectively, after irradiation. Immunohistoehemical method was employed to assess EGF and EGFR in the intestinal tissue of the mice. Results After the neutron radiation with 2.5Gy dosage, the expressions of EGF and EGFR in the cytoplasm of mucosa epithelial cells and crypt cells were obviously up-regulated within 1 day, decreased after 142 days, increased again on 3-7 days, reached the peak value at the 5th day, and returned to normal values in 14 days. Whereas EGF and EGFR were increased at 6 hours and progressively decreased from 12 hours up to 4 days after 4.0 and 5.5Gy neutron and 12Gy g-ray radiation. They were increased progressively within 3 days, reaching peak value on the 3rd day, and returned to normal values 5 days after 5.5Gy g-ray irradiatiorL Conclusions The expressions of endogenous EGF and EGFR showed different regularities after neutron and g-ray radiation, and they were involved in the pathologic courses of radiation damage and recovery of the intestine.