ABSTRACT
Objective To study comparatively the changes in epi th elial growth factor (EGF) and its receptor (EGFR) in injured intestine induced b y neutron and ?-ray irradiation in mice and their significance. Method s 350 male BALB/C mice were irradiated with neutron and ?-rays, and t hey were sacrificed at 6 and 12 hours and 1, 2, 3, 4, 5, 7, 10, 14, 21 and 28 da ys, respectively, after irradiation. Immunohistochemical 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 E GFR in the cytoplasm of mucosa epithelial cells and crypt cells were obviously u p-regulated within 1 day, decreased after 1~2 days, increased again on 3~7 days , reached the peak value at the 5th day, and returned to normal values in 14 day s. Whereas EGF and EGFR were increased at 6 hours and progressively decreased fr om 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 3r d day, and returned to normal values 5 days after 5.5Gy g-ray irradiation. Conclusions The expressions of endogenous EGF and EGFR showed diffe rent regularities after neutron and g-ray radiation, and they were involved in the pathologic courses of radiation damage and recovery of the intestine.