Objective To evaluate the effect of rhIL-11 on radiation injury to the intestinal epithelium and cells cycle of intestinal epithelial cell in mice irradiated with 3.5 Gy neutron. Methods The morphology of the small intestinal epithelium, crypt cells necrosis, and cell proliferation were observed of the epithelial cells of the irradiated mice. Cell cycle of the epithelial cells of the small intestine of the mice was examined by flow cytometry. Results rhIL-11 pretreatment before and treatment after irradiation could accelerate the repair of small intestinal mucosa in irradiated mice. G 2/M block which occurred in the irradiated small intestinal epithelial cells and the rhIL-11 treatment might significantly increased the proportion of cells at S phase. Conclusion rhIL-11 could significantly exert a preventive effect on the small intestine against radiation injury in neutron irradiated mice, with an impact on cell cycle of the intestinal epithelial cells.

Objective To understand the radiation protection effect of pre-irradiation administrations of nilestriol on the mice with bone marrow type of acute radiation syndrome after irradiation with 60Co γ-rays,along with its mechanisms for improvement of hematopoiesis.Methods The nilestriol administration protocols were prepared by analysis of peripheral blood cell counts and survival rate experiment on mice.The mechanisms by which the pre-irradiation twice administrations improved the post-irradiation recovery of bone marrow hematopoiesis were studied by the analysis of the surface marker of bone marrow hematopoietic stem/progenitor cells of mice and by the inspection of hematopoietic progenitor cell colony and by using histopathological assessment of bone marrow.Results Pre-irradiation administration of nilestriol at two-or three-day intervals had been shown to increase survival rates up to 100％ in mice exposed to 9.0 Gy γ-rays,which was superior to a single administration (20％,x2 =21.66,21.66,P ＜0.05).The pre-irradiation administration both at one-day or two-day intervals were capable of improving the recovery of peripheral blood counts,including white blood cell (WBC),red blood cell (RBC),and platelet in mice exposed to 6.5 Gy (F =21.33,100.9,49.34,19.19,P ＜ 0.05),showing the better effects than a single administration (F =17.11,63.38,21.89,14.37,P ＜ 0.05).The two-day-interval administration of nilestriol could significantly increase the numbers of bone marrow hematopoietic stem/progenitor cell counts (t =8.58,2.80,P ＜ 0.05) in mice on day 10 after 6.5 Gy irradiation.This also could be capable to significantly improve colony formation,with there being statistical difference compared with single administration(t =4.29,6.34,P ＜ 0.05).Also the administration at two-day-interval were also usefull in reconstruction of hematopoietic cell hyperplasia of bone marrow of irradiated mice.Conclusions As compared with conventional single admination,the pre-irradiation multiple administrations of nilestriol showed significantly improved radiation protection effects.Considering a nuclear medical emergency rescue,it is recommended to follow the pre-irradiation administration of nilestriol at two-day interval,which could obtain the best protection effects at minimum administration frequency.

Objective:To study the protective effect of Mongolian medicine Bateri-7 on radiation-induced intestinal injury in mice.Methods:C57BL/6J male mice were randomly divided into control group, irradiation group and irradiation plus drug administration group, with 10 or 15 mice in each group. For irradiation group, the mice were given a single dose of 12 Gy 60Co γ-rays with total body irradiation. For drug treatment, the mice were gavaged with Bateri-7 (530 mg/kg) 7 d before irradiation until 3 d after IR. At 6 h and 24 h after irradiation, the Tunel positive cells in intestine were detected immunohistochemically. At 3.5 d after irradiation, the structure of intestinal villi was observed by HE staining, and the BrdU and Ki67 positive cells were detected immunohistochemically. The expression levels of IL-6, TNF-α and Cxcl-5 were detected by qPCR. The FITC-dextran in peripheral blood was also determined. Results:The survival of irradiated mice was significantly increased by Bateri-7 ( χ2= 5.84, P < 0.05), but there was no significant difference in weight between two groups ( P > 0.05). The villi length of small intestine in the irradiation plus drug group was significantly longer than that in the irradiation group ( t = 20.24, P < 0.05), and there was no significant difference in the depth of intestinal crypt between two groups ( P > 0.05). At 6 and 24 h after irradiation, the number of Tunel positive cells in intestinal crypts in the irradiation plus drug group was significantly reduced in comparison with the irradiation group ( t = 3.52, 2.90, P < 0.05). At 3.5 d after irradiation, the level of FITC-dextran in serum and the expressions of IL-6, TNF-α and Cxcl-5 in small intestine of mice in the irradiation plus drug group were significantly lower than those in the irradiation group, respectively( t = 6.92, 7.01, 7.18, 13.16, P < 0.05). The number of BrdU and Ki67 positive cells in the crypt of mice in the irradiation plus drug group was higher than that of the irradiation group ( t = 3.91, 2.57, P < 0.05). Conclusions:Mongolian medicine Bateri-7 can effectively alleviate irradiation-induced intestinal injury of mice, which may have a good preventive and therapeutic effect on radiation enteritis.