Objective : To compare the effect of dexamethasone on rat radiation-induced proctitis administrated by two different ways which were the intraperitoneal injection and clyster. Methods: Thirty-two SD rats were randomly divided into 4 groups, which were defined as follows : unirradiated and clystered by normal saline( group A ); irradiated and clystered hy normal saline( group B );irradiated and clystered by dexamethasone( group C ) ; irradiated and dexamethasone was given by intraperitoneal injection ( group D ).The pelvis of rats received irradiation with a dose of 16. 5Gy except group A. All rats were killed ten days after irradiation. The levels of radiation-induced proctitis were scored after HE staining of the rectum. and the expression of serum TNF-α was detected by ELISA method and TNF-α mRNA expression level of the rectum was detected by RT-PCR. Results: Dexamethasone showed good effects to treat radiation-induced proctitis by intraperitoneal injection as well as reduce the expression of TNF-α of the serum and the TNF-α mRNA level of rectum, while it demonstrated no effect on radiation-induced proctitis when administrated bv clvsis. Conclusion: It is a right way for dexamethasone to treat radiation-induced proctitis by systemic administration .%目的:比较地塞米松分别采用腹腔注射及灌肠方式治疗大鼠放射性直肠炎的疗效.方法:32只SD大鼠随机分为4组:未放疗+生理盐水灌肠组(A组);放疗+生理盐水灌肠组 (B组);放疗+地塞米松灌肠组(C组);放疗+地塞米松腹腔注射组(D组).每组8只大鼠,除A组外所有大鼠盆腔均接受16.5Gy剂量的放疗.放疗10天后处死所有大鼠.直肠标本进行HE染色病理检查,并行肿瘤坏死因子-α(TNF-α)mRNA的RT-PCR检测,处死大鼠前抽大鼠静脉血行血清TNF-α的ELISA检测.结果:地塞米松灌肠并没有显示出治疗大鼠放射性直肠炎的作用,而地塞米松腹腔注射可以明显减轻大鼠直肠放射性炎症,并可以减少直肠局部TNF-α及血清TNF-α的表达.结论:地塞米松全身给药治疗放射性直肠炎是正确的给药方式.
展开▼
